What is this?
 

This may or may not be automotive related; I just don’t know what it is. I found it in my late father’s garage in a drawer. The bulk of the body is for holding a AA battery with some electronic circuitry at the end behind the round grill. Thanks.

Another shot, inside without the battery. Thanks again in advance.

Electronic Mosquito Repellent?

Uses high frequency sound, sometimes you can just barely hear the difference between it being turned off and when it's on when held up to your ear. Of course that would require a known good battery to test it.

Dad was holding out on us! Thanks very much!