Found this behind one side of a door frame that was being removed for replacement. It appears that this ball lodged itself into the wood at a pretty high rate of speed. My initial thought was that it is some sort of non-lethal or crowd control ammunition but it had to be absolutely moving to lodge itself into solid wood like that. Doesn’t seem very “non-lethal”.
The ball is a pretty hard, light plastic. It doesn’t feel squishy at all like rubber bullets I’ve seen.