First I want to say shame on you for taking warning shots!!! Where did those bullets go?
Second trail cameras are cheap these days so getting one to figure out what may or may not be staring at you is a way better idea versus just putting rounds down range... Especially when you admit that your are not sure what your shooting at!
Third you should also get a better flash light... At 50 feet if you can not see what your putting the beam on your light is poor!
Fourth since the critter is not around during the day why not go look at the tracks in day light hours or even call the local conservation officer to see if he has any information about problem critters!
Good luck in figuring out what is staring at you!