i think hes merely a kiddo cracker. Try sniffing to confirm the fact. If yes, then u can play with him. If u dunno hw to play. Perfect time to learn. Nothin is better when some kiddos lay themselves on to your trap thinking they are the predator.
It's very common/easy to crack into wifi even if u hide your ssid/encrypted. So cant help it. Gotta find out his ip. Ban it. If u jz wanna make love not war.
wifi stealing detector