How do I get rid of a smell in my closet?

Wash the walls and ceiling with a vinegar water solution. If you have carpet in there, sprinkle with baking soda and leave overnight, then vacuum up. Smell all your clothes and see if you can find an item or two that might be the culprit. Not to long ago I attended an event and I sat by a bunch of stogie smokers. My clothes reeked when I returned home. I don't mind pipe or cigar smoke, but it does make your clothes smell. I left the windows down in the car overnight, and washed what I was wearing and kept quarantined so they did not stink up my closet.

Have you washed everything down and repainted? Stinks from What? Is it carpeted? May need to remove that.

If the closet has a wall off a bathroom it could have had a leak and smell because of water damage. Pull back carpet or piece of floor covering to have a look. Ir it has an access hole in the ceiling look up there. Rodent droppings could be the cause of the smell.

Try ripping out carpeting. Padding may be rotted, as well.

Vacuum.

Scrub all floor and wall surfaces.

Use Odo Ban to wipe down walls, after cleaning.

Place containers of baking soda in closet.

Check for entry points of insects, rodents and fill these spaces.

If there's an attic above this closet, check there for evidence of rodents, as well.