The Adventures of Superman
The Stolen Costume
S1 E13:
The secret identity of Superman is almost exposed when a sneak thief fleeing from the police slips into Clark Kent's apartment, finds the special Superman costume, and takes it to a notorious racketeer, in the thrilling adventure "The Stolen Costume." Unable to reveal his identity, Clark Kent regains the costume through a clever trick.
Starring
Norman Budd, Frank Jenks, Dan Seymour