I have a 1967 Camaro SS. The wipers run constantly. When Ihave the switch out of the dashboard, the switch works fine. When I try to install it into the dashboad I get a spark and the wipers run continious. Any suggestions? I think the switch is defective, but I'm oopen to any suggestions. The car has been totally rewired with a painless wiring system.

sounds like a short somewhere, and the switch is grounding itself somehow