1967 Chevy Camaro brake lights

Brakes problem
1967 Chevy Camaro V8 Manual

Ok, I have a stumper. My drivers side brake light works, the passenger side does not. When I turn the head lights on at night the passenger side does not work still, and the drivers side that was working, no longer works, no parking lights in rear either when head lights are on. Any ideas, electrical problems like this drive me crazy. Thanks guys.