My dad's house is 50 years old. It's a single floor ranch over a full (unfinished) basement. The odor is prevalent in the 2nd spare bedroom located (on the front corner of the house) and adjacent to the master. The odor can only be smelled when standing. I've literally put nose to carpet, air ducts, electrical outlets without leading to a source. I've accessed the attic without noticing the odor.

I've read nearly all the postings regarding funky erroneous smells and nothing pans out for me. Can a dead mouse in a wall be permeating the air through the sheet rock?