I had that problem with my 98 Contour in one of the headlight assemblies. I pulled the bulb and removed the cover over the headlight level gauge. Then I used a hair dryer to blow air into the opening for the bulb, with the level gauge opening acting as an exhaust. It seem like it took several hours, but I finally got the interior dry. Compressed air could work fine, but I didn't have a source so that's why I used a hairdryer.
After reinstalling the bulb and level gauge cover I haven't had anymore water in the headlight going on 5 months.
