When wiring a 2-way switch circuit, all we want to do is to control the black wire (hot wire) to turn on and off the load. This simple diagram below will give you a . The diagram below will give you a good understanding how this circuit is wired. 4-way switch wiring diagram. Power at Light 4-Way Switch Wiring Diagram. Need a Light Switch Wiring Diagram? Whether you have power coming in through the switch or from the lights, these switch wiring diagrams will show you the . Looking for a 3 way switch wiring diagram? Here are a few that may be of interest. Clear, easy-to-read diagrams for household electrical light switches with wiring instructions. Either way, complete these five steps for 3 way light switch wiring: Turn off the correct circuit at your electrical panel. Add an electrical box for the second three-way switch in the basement. Feed a length of 14-3 type NM cable (or 12-3, if you're connecting to 12-gauge wire) between the two boxes.