Light Switch Wiring Diagram (Single Pole) - Easy 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 light. How to Wire and Install Single-Pole Switches - The Spruce How to Wire and Install Single-Pole Switches. By Timothy Thiele. Updated 07/30/18. Pin Share Email DonNichols / Getty Images . 01 of 06. Note the switch wiring.