Punky Brewster: Love Thy Neighbor (1985)

Originally aired November 17, 1985. On Halloween night, a woman named Isabelle Peavy behaves rudely to the children in Punky's building and refuses to give them candy. Punky and Cherie enter her apartment to play a joke on her, but their plans go awry when Brandon accidentally gets left behind. The next day, Henry goes over to retrieve the dog, and he ends up learning some interesting information about Isabelle. (Synopsis from TV.com) Watch episode on NBC.com.