Ghost Girl is a Watch floor where Kayako Seaki 'Grudge Girl' is standing in front of the elevator and does nothing. When the elevator doors close and the lights turn off then on, she then appears inside the elevator where white light emits from it.
Fun Facts: There is a chance for Baldi to appear on the floor, almost guaranteeing a chance you will die. You can also temporarily explore around the floor for a little bit.