Bewitched (1964)

S3E8 Dangerous Diaper Dan

Diaper Dan, a shadowy figure, infiltrates the Stephens' home to pilfer advertising concepts from Darrin for a competing firm. The truth surfaces only after a heated argument between Samantha and Darrin, which Dan eavesdrops on. He then sends flowers to the house, prompting Samantha to investigate the delivery and uncover the bugging device. Realizing Dan's deceit, she and Endora confront him, making his life quite difficult.