Removing an Unknown Odor from Wood Cabinets

I had the same problem and I sprinkled baking soda on the floor of the cabinets and left it there for a month or more. You can wipe it out and add more if you still notice the smell. After that treatment if you still have a smell, paint or varnish the interior of the cabinet.

Try siting a few dishes of vinegar in the cabinets, or, polish them inside and out with a very good lemon furniture polish or oil.

I think I know what you mean. I bought a sideboard at an auction sale that had an "old" smell. I used dishes of baking soda, coffee grounds, and put in eucalyptus. I wasn't really happy with any of those, but they all helped. Additionally, I would try activated charcoal, and maybe washing out the inside with baking soda and water, or perhaps vinegar and water. (Don't mix the two.) Eventually, I re-sold the sideboard, so it became some one else's problem.