Help For Your Dimmer Switch Wiring - Ask the Electrician Wiring a Dimmer Switch. 3 Way Dimmer Switch wiring diagrams to help you wire a single or 3-way dimmer switch. Don’t get confused with dimmer switch wiring. As mentioned, a double pole dimmer switch is really a 3way dimmer switch, which is wired the same as a standard 3-way toggle switch. How to Connect a Dimmer Light Switch to a GFI Outlet | eHow www››Home Repair & Maintenance›Electrical RepairsConnect the black wire from the GFI to one of the two dimmer switch wires. Connect the black wire from the light fixture to the other switch wire, using wire nuts. Wrap all the insulated wire nut connections with electrical tape, winding the tape clockwise overlapping from the nut onto the insulated wires.