condensation in head light!!!

i have taken my passenger head light out twice now to seal it up. i disasembled the light and used cauk, the 2 time i even filled it up with water and to c if it leaked any where and it didnt. i cant figure out how it gets in there. does anyone have any ideas??

I couldn't find where my Grand Prix headlight was getting water in it either so eventually I just bought a new one. Check for really microscopic cracks on the housing and check that none of the o rings on the bulbs are broken.

It did that to my car i just left my covers of the bulbs off and it solved it.