Bewitched (1964)

S2E26 Baby's First Paragraph

Endora is tasked with babysitting Tabitha and vows to refrain from using her magical powers. However, when Gladys boasts incessantly about her intelligent baby nephew, Endora can’t resist the temptation and casts a spell to make Tabitha speak. The news spreads like wildfire, and every newspaper clamors for a scoop on the remarkable child. This drives Samantha and Darrin into a rage at Endora's antics. To clarify the situation, Endora reveals that her secret was merely her ventriloquist skills, leaving everyone shocked but ultimately amused.