I have two lights on two separate circuits connected to separate switches in the same box. The lights control overhead lighting in the same room and there's no reason (code/etc) they shouldn't have been on the same circuit in the first place. I don't want to rewire the ceiling and would like one circuit to be completed only if current is flowing through the other circuit. Is there a type of switch that does this or, alternatively, a type of switch that toggles two circuits simultaneously?
Edit: A simple double pole switch won't work, because one of the two switches is 3 way.