It wasn’t that funny. 
A Communist Party costume party! But of course! (Was it a 1920’s style communist party party?)
It was, but only for 20 minutes, in 1960.
I had a similar problem. Intermittent beeping in the bedroom. It never lasted long enough to even determine the direction. Usually it was in the middle of the night. It just about drove me crazy! (I know, not too long a drive. Ha!) I eventually found the culprit. It was an old watch in a drawer.
HA! I knew it! 
Your “symptoms” reminded me of a story I read on one of those “tech support funnies” sites a while back. This guy’s computer was beeping for no reason and it turned out to be a pager that had fallen under the desk…
Well, sure. But you said it would be in my drawers.
It was in my desk.
So there.
Now, if a Communist Party Official had spats on his shoes sometime during the party, what would he use to wipe them off?