Try using a hair dryer blowing through the hole where you put the bulb, or else blowing carefully on the front of the lens from the outside. Something I use with my 1953 Triumph sports car signal lights and brake lights where I get condensation as a result of -30 degree F temperatures in winter, is taping to the inside of the light unit one of those little packets that come with new electronics equipment to keep them dry - can't remember what they're called. Don't know where you'd afix it inside the light unit though, without messing up your beam pattern.
Will Keith
1996 Contour SL Duratec, auto.