Originally Posted by modelaman57
I am an insurance restoration contractor, very experienced. I know that just a tiny, tiny amount of smoke residue missed inside a wall cavaty can sneak out through the small openings in, say an electrical outlet, and smell up the whole room. When there has been, even a small fire in a home, all drywall is demo'd, framing cleaned, and then sprayed with a special sealer paint to lock in any odor. You probably are picking up an odor from way up inside somewhere.
That was my thoughts, I have an employee that was a contractor in FL and he was telling me about a hospital they built and because the heat ducts were dumped in the parking lot for a month before using they had a slight mold problem in the first floor heat ducting, they had to rip out and replace.
Or could be a simple as when the house was framed, it rained and had a small amount of mold.