From Broadway World, 12/22/20:
The Players, New York's fabled social club for the dramatic arts and its patrons, has posted a "ghost light" on the balcony of its Gramercy Park clubhouse as a reminder that live theatre and convivial gathering of its members will return.
Generally in the form of a single-bulb floor lamp, the ghost light is traditionally placed on a stage to illuminate the space between performances or show runs. Practically, the lamp lights the stage apron of the darkened theatre to prevent falls into the orchestra pit. Plus, in a setting full of haunting legends, the ghost light discourages mischief by resident spirits.
Club President Michael McCurdy said, "The ghost light will stay on until our members are back home."