light to a traveler between two three way switches. Make sure the breaker is off to this circuit (not just turning off a switch) before fooling with it as you may think you have a dead circuit testing one traveler or a switched hot to ground and the other traveler is still hot. Go to: http://www.wfu.edu/~matthews/courses/p230/switches/3way/variations.html
to see what I'm talking about. Be darned sure you fully understand this before getting back into it. You can tell if your switching scheme is three way by looking at the switches...they'll both have three wires connected. Luck, Kizmet