The lightbulb that seems to react to Ross' actions is commonly known in the theatre as a "ghost light." While considered by many a superstition and by others a practical safety measure, the ghost light is ALWAYS to remain on, even if the rest of the theater is dark. One legend of the ghost light says that its purpose is to provide light for the theatre ghosts to perform their roles (theatre ghosts are often said to have been actors). Allowing the ghosts space and light to perform is said to appease them and prevent them from cursing running productions.
Walking across the stage, Ross whistles the theme song of the show.
One of eleven episodes where the Midnight Society didn't leave and douse the fire with the water-bucket (Tucker was cleaning trash).
For some unknown reason this episode isn't on paramount streaming.