Little House on the Prairie (1974)

S3E5 The Monster Of Walnut Grove

On Halloween, Laura's vivid imagination leads her to believe she witnessed Nels decapitating Mrs. Oleson. Excited by the shocking news, she shares her sighting with Nellie and Willie. Aware that their mother is actually away, the Oleson children decide to have some fun by further frightening Laura. The situation is eventually resolved when Mrs. Oleson returns, clearing up the confusion and restoring order.