How to locate source of foul odor
Does anybody know how to locate a bad odor source? We have a bad smell that is similar to the smell of cold grease in an old skillet. It never gets stronger than that. We thought it might be a dead squirrel in the interstitial between our 1st floor ceiling and 2nd level floor. We have a 16-inch space there with manufacturered trusses.
We have had squirrels get in there before and actually had to remove some stair treads to get one out one time. But we have not heard anything lately. (Our dog would have heard it if one was in there again.) But the smell never gets to the rancidness of decaying meat.
The odor is confined to a specific area of the house; in the living room & master closet which shares a wall with the living room. The only other thing that is in that area is the sanitary sewer line from the 2nd floor bath. It runs in a chase that is common to those rooms. We do not see any water leakage though. The odor is not constant either. It gets worse from time to time but never really goes away completely.
We are at a loss as to what kind of service company we would call to investigate this. Any suggestions? Do termites make an odor? I have heard they create methane...
Thanks to all...