Brake Lights

I have a 1996 Corolla with brake light problems. When the headlights are on, the rear window brake light is dimly lit, and when I touch the brakes, it becomes bright but I loose the rear lights. I am hoping that one of you eletrical toyota gurus out there can tell me where to start looking for the short.
thanks

Well... Have had a problem earlier that reminds me of yours...
When i pressed the brake pedal i lost all my lights on my car and i got left markers turned on...
The problem was a light bulb that was gone bad... So check all your light bulbs to see if that helps on the problem :)