Ghost light (theatre)

A ghost light is an electric light that is left energised on the stage of a theatre when the theatre is unoccupied and would otherwise be completely dark. It typically consists of an exposed incandescent bulb, CFL lamp, or LED lamp mounted in a wire cage on a portable light stand. It is usually placed near centre stage. Ghost lights are also sometimes known as equity lights or equity lamps, possibly indicating their use was originally mandated by the Actors' Equity Association, or Equity.