Bewitched (1964)

S6E18 Samantha's Secret is Discovered

Phyllis unexpectedly discovers Samantha's magical abilities and is left feeling bewildered. After six years of secrecy, Samantha reveals her identity as a witch and demonstrates her powers to Phyllis. Eager to share this revelation, Phyllis tells Frank about Samantha, but when Samantha attempts to showcase her abilities, they mysteriously vanish. This turmoil leads Phyllis to believe she is losing her mind, prompting her to check herself into a nursing home, convinced she is going mad.