If you have the AC below the closet you will have the vent on the front in bad shape or like mine was falling apart. They do not make them any more so we must make do. I read on this forum a while back and someone said to put a piece of metal over the whole. That started me thinking,.... and the problem is now fixed.
A piece of sheet metal some edging from some forgotten project, set of hinges, and 2 draw clips mix with some paint
and put on in place of that ugly vent and cover.