i have a coin button as well as a coin door. I had my CP fully wired and done before i wired up the coin door. I Took the ground wire from the coin door, and just twisted it up with the ground from my coin button with a female disconnect, plugged it onto the ground on my coin button microswitch..did the same with the wire from coin door to coin button. Basically just spliced them into the same disconnects and ran them through my coin button microswitch.