Spooks Run Wild (1941)

The East Side Kids are sent to summer camp, and shortly after arriving they encounter a mysterious man named Nardo (Bela Lugosi). Naturally, the Kids assume Nardo is the "monster killer" they've been warned about. Their theory is strengthened when they see Peewee (David Gorcey), seemingly risen from the dead after getting shot, walking around Nardo's house in a zombie-like trance. The Kids take it upon themselves to capture Nardo before he can kill anyone else.