Oblivion Battery

S05E01 Something's Going Around

Peter becomes sick, prompting Louis to call a doctor (Stanley Ralph Ross) he recently met. Unbeknownst to them, the doctor has sent a batch of potato chips that induce an allergy to ghosts, and Peter is the only one who has consumed enough to be affected. The doctor provides them with additional chips, but the Ghostbusters remain unaware that he is actually a ghost himself. They must find a way to build up their immunity to the ghost allergy before it's too late.