Step 4: Inspect Switch Wiring
Check the terminals on the switch with a voltage tester to make sure the power is off. Examine the switch, noting which wire is attached to which screw. Before disconnecting the wires, flag or label them so you’ll remember which one is which. Since the switch pictured had a black and white wire running through it, the white wire was marked with black electrical tape to indicate it was hot.
Step 5: Disconnect Wires from Switch
Loosen the screws on the switch that hold the wires in place, and carefully remove the wires. If the wires were installed in the back of the switch with push-in terminals, insert a small, slotted screwdriver in the slot next to each terminal to release the wire. If a bare copper ground wire is attached to the switch, disconnect it as well.
If the end of the wires are in good shape, you can reuse them without cutting or re-stripping. However, if the ends are damaged, snip them back to good solid wire, and use your wire strippers to remove the sheathing to expose about 1/2” of bare wire.
If there are other wires inside the electrical box connected with wire nuts, check to see that the connections are tight by turning the wire nut clockwise. If the inside of the electrical box is dusty, vacuum it out.
Step 6: Connect Wires to New Switch
Hold the new switch so the “off” position is pointing down. If you are attaching the wires using the mounting screws on the side of the switch, use the tips of stripping pliers or needle-nose pliers to gently bend a hook in the wires to fit around the connection screw. Bend the wires in a clockwise direction, so they will be pulled onto the terminals when you tighten up the screws.
Hook each wire around the connection screw, making sure your labels match the old switch, and tighten up the screws to secure the wires to the switch. If you have a ground wire, connect it to the green screw on the switch.
Alternatively, you can insert a straight wire beneath the brass plate next to the screw and tighten the screw to hold it in place, or use push-in connections on the back of the switch if available; but both methods are considered less secure than screw mounting.