The ghost light is a theater tradition. Leaving an electric light on, usually on center stage, when the theater is unoccupied and would otherwise be dark. Ostensibly it's for safety, to keep someone working in the theater from falling into the orchestra pit or tripping over wires and set pieces. Superstition would like you to believe it is to appease the theater ghosts, hence the name. To allow the ghosts to perform on stage to appease them or to scare them away.
I prefer the symbolism of the ghost light. It serves as a symbol that the stage is not forgotten. It has not been abandoned. It is not the end. It's only a brief interruption between performances. It's an interlude, an intermission, not a finale.
That's where we are right now. As things reopen, we remember that this experience has been an intermission. It was never intended to be forever, though it might be something we face again. We were not forgotten, we were not abandoned. The show will go on, even if it will be a while before it fully does so.
Right now, we take solace in the fact that the ghost light still burns.