The Alfred Hitchcock Hour (1962)

Season 1: Episode 20

Alice Pemberton is a busy-body housewife who injects herself into the personal lives of everyone she knows: friends, relatives, her husband's business associates. Unfortunately she fails to realize that her constant attempts to give advice are alienating everyone. Her husband John is patient. He tries to tell her that her annoying behavior will cost them the last few friends that they have left. She refuses to listen. So, John decides to poison her.