Wires running along the floor are unsightly and may pose a safety hazard. Need a new phone jack in your bedroom or installing speakers for your home theater system? While you could string the wires along the floor, it’s best to snake the wires inside walls or under floors.

Wiring new construction before the drywall goes in is a piece of cake compared to fishing wires through existing walls and floors. But with careful planning, a few special tools, and the right techniques, running wires in the walls of your home may be easier than you think.

If you’re not up to the challenge, consider running the wires in special hollow moldings that take the place of standard crown molding or quarter-round.


Here are the tools you’ll need for running wires:

  • Drill and bits
  • Stud Finder
  • Measuring Tape
  • Flashlight
  • Drywall Keyhole Saw
  • Fish Tape or Wire Coat Hanger
  • Electrical Tape
  • String and fishing weight

A fish tape is essential for pulling wires through walls. It is a flexible steel tape with a hook or eye on the end that allows you to thread it through openings and cavities. Fish tapes come in different lengths, with 25 feet generally enough for most residential wiring projects. You attach your electrical wire or cable to the fish tape’s hook, then pull the tape through the wall to pull your wire along with it.

A wire coat hanger can also work in a pinch. Straighten it out as much as possible, and use electrical tape to attach your wires. It may not be as easy to maneuver as a fish tape, but a coat hanger costs almost nothing.

Before You Start

Before you start running any wires through existing walls, keep these important preparatory steps in mind:

Most areas allow homeowners to install their own low-voltage wiring, such as phone lines, computer network cables, and speaker wire‌s. However, check your local building codes to be sure. Running new high-voltage electrical wiring requires an electrician’s license in most jurisdictions. It’s crucial to follow proper permitting and licensing regulations for safety.

Make sure you use UL-rated in-wall wiring that meets local building and fire codes. Examples include CM, CMR, or CMP for computer networking and CL2 or CL3 for speakers. Using subpar wire could create a fire hazard inside your walls, so use wiring designed specifically for in-wall use.

Always turn off the main circuit breakers in your electrical panel before you begin. This reduces the chance of ‌electrical issues should you accidentally cut or drill into existing wiring. Working with the power off prevents potentially fatal mistakes.

Keep speaker, computer, and phone wires at least 6 inches away from standard 120V electrical wiring for safety reasons and to reduce interference. Separating low-voltage wiring from AC power lines minimizes radio frequency noise and cross-talk.

Whenever possible, run your wiring through interior walls since exterior walls contain insulation, vapor barriers, and structural bracing that can obstruct wires. Interior walls have fewer potential obstructions.

Planning Your Wiring Route

Careful planning is crucial before you start running wires through walls. Follow these tips to map out the optimal wiring route. 

Examine the existing electrical outlets on the wall, and make sure your planned wiring route stays at least one stud cavity away to prevent interference.

Go up to the attic with a stud finder to see if the route is accessible from above and free of hidden obstructions like plumbing pipes and HVAC ductwork. Scanning the wall with a metal-detecting stud finder can also locate hidden obstacles.

Calculate the length of wire needed by measuring the start and end points, adding extra for connections, and tacking on an additional 10% as a buffer. Having too much wire is better than coming up short halfway through.

Drill a small pilot hole where the outlet or other termination point will be, and use a coat hanger to feel around inside the wall cavity for blockages. If clear, you are ready to start running your wires.

How to Fish Wires Through Walls

Follow these steps to fish your wiring through walls:

  1. Turn off the power and use a stud finder to locate an open cavity between studs for the outlet or switch box.
  2. Drill a hole in the drywall and insert a small inspection camera, if available, to examine the route. Otherwise, use a stiff wire to feel for obstructions.
  3. Once the route looks clear, cut a hole in the drywall for the outlet or switch box using a drywall saw. Don’t install the box yet.
  4. Go to the attic or basement and drill a hole through the top or bottom wall plate in the same stud cavity.
  5. Attach your electrical wire to a fish tape and feed it through the hole until it reaches the outlet box opening.
  6. Pull the wire until several feet protrude from the outlet box hole. Leave plenty of extra length for connections.
  7. Feed the wire through the outlet box, attach the box to the wall, then terminate the wires.
  8. For multiple connection points, drill additional outlet box holes and feed the wire through each one as needed.

Fishing Wire Under Floors

For running speaker wire or networking cable to the middle of a room:

  1. Drill a hole near the wall at your starting point and another hole at your endpoint in the floor.
  2. Feed the fish tape from the start to the endpoint and attach the wire.
  3. Pull the wire through the drilled hole at the endpoint location.
  4. Leave plenty of slack in the wire at both holes to allow connections.
  5. Install outlet boxes, conduits, or other covers to terminate the wires and conceal them. Be sure to match materials like linoleum flooring when patching floor holes.


Patch drywall holes with spackling compound when wiring is complete. Sand smooth when dry. Fill small floor holes with matching wood filler putty. You can patch larger holes by filling floor holes.

Label your wires with their location and endpoints as you run them to keep everything organized. Avoid pushing wires straight across ceilings, where they’ll be visible. Route them along the edges of the room instead.

cutting electrical wires
Image credit: Canva

Use special wall plate inserts with brush openings for horizontal wiring runs to conceal the wires. Consider surface-mounted wire raceways as an easier alternative to fishing wires in walls. Raceways contain channels to route wires.

So, Is Running Wire Through Existing Walls DIY-Friendly?

Running new low-voltage wiring inside existing walls is a doable DIY project for a homeowner comfortable with basic electrical and drywall repairs. The right planning and tools make it less daunting than it may seem at first glance. Thoroughly map out your wiring route to avoid surprises, and have the materials needed for drywall patching on hand. Taking it slow and steady is the key to success.

That said, if the wiring project involves high-voltage electrical lines or if you need to run wires over long distances. They have the expertise to complete complicated wiring jobs safely and compliantly with building codes. The small cost of hiring an electrician can give you peace of mind that your walls won’t turn into fire hazards. For extensive whole-home wiring renovations, there’s no substitute for a pro.

FAQs About Running Wire Through Walls

Do I need to get a permit to run the wiring?

Permits usually aren’t required for low-voltage wiring like a speaker, coaxial, or Cat5 cable. But call your local building department to check the rules for your area. Electrical wiring does require a permit and a licensed electrician in most cases.

What if there's insulation in the walls?

You can carefully cut through fiberglass batt insulation using a long drywall saw to carve a path for your wires. Try to avoid compressing the insulation since this reduces its effectiveness. Or you can use foam backer rods to displace and divert the insulation away from your wire route.

Is it OK to run wires behind wallpaper?

Removing wallpaper before running new wires is better to avoid damaging the paper surface. Wire bumps may show through freshly hung wallpaper. Removing wallpaper also allows you to repair drywall holes and dents properly.

How do I fish wires around blocking?

If you hit a fire block or other obstruction, one option is to drill small holes straight through it every 16 inches to thread your wires through. An easier method is to double back and take a different route between stud cavities to avoid the blockage.

What do I do if my wire gets stuck?

Don’t pull hard, or you may damage the wire. Try feeding the wire back in the direction it came from to dislodge it or wiggle the end around the obstruction. In a worst-case scenario, you may need to cut the wire, re-fish through, and splice it back together.

Editorial Contributors
avatar for Jonathon Jachura

Jonathon Jachura


Jonathon Jachura is a two-time homeowner with hands-on experience with HVAC, gutters, plumbing, lawn care, pest control, and other aspects of owning a home. He is passionate about home maintenance and finding the best services. His main goal is to educate others with crisp, concise descriptions that any homeowner can use. Jon uses his strong technical background to create engaging, easy-to-read, and informative guides. He does most of his home and lawn projects himself but hires professional companies for the “big things.” He knows what goes into finding the best service providers and contractors. Jon studied mechanical engineering at Purdue University in Indiana and worked in the HVAC industry for 12 years. Between his various home improvement projects, he enjoys the outdoors, a good cup of coffee, and spending time with his family.

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