Who is the Ghost?

David woke up, stretched his arms and legs, took a look at the wall clock, it was twenty-six minutes to Nine pm. His breath smells of alcohol; his entire body smells. He still had time, so he decided to rush his bath before she came. He unlocked the door but shut it.

While under the shower, he ran through how it will all play out in his head. He won't allow that ghost to touch him again. Once he sets his eyes on her, he is so calling her name and let her be gone. If he can successfully free himself from this girl or ghost, he will give skirt-chasing a hard break.

Lost in introspect, he was brought back to his living nightmare by a soft knock on the door. He kept quiet waiting to be sure it wasn't in his head. The knock came again, this time louder.

Should he answer or not? Or just keep quiet till she gets exhausted from knocking and leaves? But she will just return the next night and the one after that till he answers. Should he just walk naked