I live in a two story house, with a cement floor crawl space. It always seems damp down there but we don't have any water problems. The house is about 25 years old with drywall walls and wood floors. I should mention that our home inspector recommended getting a ridge vent when we replace the roof next. We have found mold in numerous closets, on the 1st and 2nd floors, one closet is adjacent to a bathroom. When we first moved in I did notice some mildew in one of the closets. I cleaned it with bleach and painted etc. (we never close the closet doors to increase circulation). Also, I live in NY which has had a moist and cool summer this year.