"Alfred Hitchcock Presents" The Baby Sitter (1956)

A detective questions baby-sitter Lottie Slocum about the murder of Clara Nash, for whom Lottie had been working. Lottie exasperates the detective by her aimless chatter and her undisguised excitement. After the detective leaves, she tells a friend about the night of the murder. Lottie disliked Clara, who was separated from her husband and was seeing another man. Lottie is so vocal in her disapproval of Clara, and in her affection for Mr. Nash, that her friend wonders whether Lottie was somehow involved. Later, Lottie is threatened by the dead woman's boyfriend. She herself hopes that the situation will give her an opportunity to get closer to Mr. Nash.