It’s very hard to determine what the episode is exactly but the credits title it as Junoon (Anhonee) Episode 1. Also not sure if the credits are accurate or even if this is the right actress. So if you’re trying to find this scene, good luck with that.
Nishigandha is a doctor in this episode and there’s a headless ghost (can you see where this is going?) She is running down this hallway at about 54 minutes in and she gets to the end of the hallway to see the ghost standing there holding his head. She stands there for a second, rolls her eyes back, and falls right to the floor.