A ghost light is a light left burning on stage when the rest of the lights in a theatre are out at night. It serves the purpose of lighting the stage enough for those who leave last and enter first so that they don't kill themselves on what may be an unfamiliar set. The ghost lights are usually unique per theatre, however many consist of some sort of bulb on the end of a rolling stand.
Historically, it is argued that ghost lights may have served one or more of the following purposes:
- Kept the ghosts away from the theatre. Many theatre people are superstitious, even these days.
- Kept the theatre workers from becoming ghosts. Safety on a dark stage was as much of a concern then as it is now.
- Prevented dangerous gas pressure from building up. Previous to electricity, theatres used to use gas lights to light the stage. Some venture that there was a need to slowly vent the gas lines at all tames to prevent an explosion, and thus a small light was always left burning.