How to Wire an Illuminated Rocker Switch - Wiring Depot Aug 17, 2015An illuminated rocker switch is like a SPST toggle switch with an extra terminal which allows the light to work. You might want to review the article on toggle switch wiring before proceeding. Also relays can be used to switch higher draw accessories to reduce switch load and voltage drop. Related Articles: Toggle Switch Wiring. Relay WiringAuthor: WD Tech Wiring a light switch? Here's how. - Easy Do It Yourself Connect the "source" wire to the bottom terminal of the switch and the other black wire to the top terminal. In this picture, you can see the strip gauge on the back of the switch. This gauge is when you want to use the "quick-connect" method when wiring a light switch. Simply strip the wire to the length specified and push the wire into the hole.