Have you really examined your house for mold?
Wall coverings-Mold loves cellulose, and cellulose is used in most wallpapers. So it is not unusual for mold growth to occur on your wallpaper, especially if the room is a source of trapped moisture like a bathroom.
Wall board – Drywall can be a source of food for mold; and especially now, when there’s a major rash of lawsuits of defective wallboard that decomposes into a toxic mess when it gets damp. And of course that toxic drywall is also a favorite meal for mold.
Window Frames-Anywhere two different types of surfaces meet, there can be a gap, and a place for moisture to collect, especially when one of the surfaces is particularly attractive to condensation, like glass. That moisture can seep into those areas and feed mold colonies. It doesn’t take much liquid for mold to gain a foothold.
Bathrooms-Bathrooms are longtime culprits for being mold habitats. It’s because it’s such a source of moisture and an area to contain it in. If water can get in, so can mold.
Store rooms– Any contained area is a potential place where mold can occur, because all it takes is a little moisture trapped inside. And that moisture can come from underground seepage if you have a basement; or it can come from the external walls or any kind of plumbing or roof leak. So check your store rooms and keep them as dry as possible.
Ceilings-Leaks travel downward. So if there’s moisture above your ceiling, there’s probably mold there too. Look for roof leaks, pipe leaks, pipe condensation, defective barriers, and if you find the path of water, you’ll find the mold.
Basement– Water goes downhill. That’s what a plumber told me was the only thing he learned in plumbing school. Don’t be surprised if there is seepage in your basement or water coming from upper areas in your house. If you’ve got the moisture there, the mold will be quick to follow.
With all of these situations, dry up the water. Clean up the area, and keep it dry, or you may be looking at a big remediation project.