I went to put in an outlet with charging ports and found this monstrosity behind the wall plate. The box is filled with expanding foam, I'm guessing as some kind of support? Then painted all over. I scraped it all out, put in outlet spacers and its much better. I think there's foam around the box too, but I'm not gonna worry about that (yet).
Now I get to spend next weekend replacing all the outlets in the house just in case there's any more sketchy "fixes" ๐ซ
After cleaning and replacing:
Putting steel wool into an electrical box will definitely keep rodents out. (And hopefully just trip a breaker instead of starting a fire.)
But yeah, that's a good combo for non-electrical voids.
It's cute that you think there's a box there.