An NYU psychology student turned his Manhattan dorm room into an air rifle factory and was arrested on illegal weapons possession raps Monday, law enforcement sources told the Post.

Bernard Goal, 20, was busted after a startled maintenance crew spotted a pair of realistic looking rifles on his bed while he was out and alerted campus security.

Public safety officers swept the Texas native’s room and found four more Airsoft weapons that closely resembled AK-47s and a black Colt carbine rifles, sources said.

Goal allegedly assembled the weapons with parts he bought online and sold them for up to $500 each, sources said.

NYPD cops arrested Goal at 2:30 p.m. Monday and hit him with six misdemeanor violations of a local law that prohibits the possession or sale of air rifles and replica firearms, according to a law enforcement source.

The weapons fire pellets through compressed air and are routinely mistaken for actual firearms. They have a range of about 140 to 300 feet and can cause flesh wounds at a close range, sources said.

“It’s very scary to know there were guns one floor below me. I had no idea,” said one of Goal’s co-workers, who described him as pleasant and a hard worker. “But knowing Bernard I’m not scared.”