Theaters have a superstition that if left empty after a performance and is ever left completely dark, a ghost will take up residence. In other versions of the same superstition the ghosts of past performances return to the stage to live out their glory moments. To prevent this, a single light is left burning at center stage after the audience and all of the actors and musicians have gone.

The origin of this superstition is rooted in both practicality and further superstition itself! The practicality, of course, is that people coming into a darkened theatre cannot see what delicate costumes, sharp and pointy props and dangerous set pieces have been left lying about, and a light is important to prevent injury, property damage or lawsuits.

The other reason lends itself to further superstition. A "dark" theater is a theater without a play. There is nothing sadder to a drama artist than an empty house. Therefore, a light is left burning center stage so that the theater is never "dark". It is simply awaiting the next production.