What is the origin of the old theatre custom of having a lit lamp on stage after a show?

Question

I've seen it in movies, but can't figure it out. Is it of Greek origin, perhaps?

Answer 1

It's called a ghost light. I can't remember the origin, but it has to do with the spirits in a theatre. You wanted them to be able to see what they were doing while the company was gone for the night, otherwise they might wreak havok during your show.

Answer 2

Ghost lights keep the ghosts away, of course!

No, only kidding. (That's the legend that sprung up around the ghost lights, but truly, they came from the very real need to always have SOME light on in a darkened theatre).

In addition to what Shkspr wrote, there are very strict rules in professional theatres about who can turn which lights on. It has to do with the stage managers' and stagehands' union--only certain people are authorized to use certain lights at certain times. It might sound a bit silly, but the laws are essentially designed to make sure that only people who are properly trained are messing about with large electrical currents, and that no theatre person is being overworked or asked to do something unsafe.

The ghost light can be turned on or off by anybody. (Even, probably, the ghosts. =)

Answer 3

It's known as a "ghost light." The practical reason for having it around, of course, is that it prevents people from injuring themselves in the dark, particularly if the theatre has a deep orchestra pit.

I've heard plenty of other more interesting (and, probably, more fanciful) explanations:

-- prevent the theatre from ever "going dark."
-- appease the (seemingly) ever-present theatre ghosts.
-- (in the era of gaslights) keep some gas running through the pipes to avoid a dangerous build-up...

Etc.