Help! ... My Daughter is Afraid of Ghost

Well, everybody does.  Who wouldn't be afraid if you see something or someone who looks like those creatures in horror movies?  But what I found unusual with my daughter is that even if she has not seen any of these scary creatures in real life, yet she is afraid to be alone anywhere in the house not only at night time but even in broad daylight.  She said that she can't get out of her mind the scary scenes of horror movies she had watched on television and the horror stories she heard from her classmates.

Every time she takes a bath or do her thing in the bathroom she asks us (most of the time her younger brother) to accompany her and just stand at the bathroom door.  She won't get inside the bedroom alone.

We live in a small house, only 42 square meter area with two bedrooms and one bathroom.  The living room, dining room and kitchen are just a few steps away from each other so I really don't understand why she's afraid and always wanted someone to be at her side.

My daughter is already nine years old but she is still sleeping with us.  At the end of the year, I'm planning to have her sleep at her bedroom but with what she is behaving, I would find it difficult to leave her alone in her bedroom.  She is nearing her puberty stage and she should be using the bathroom all by herself with the bathroom door locked.

For now, I can't do anything but to tell her not to watch horror movies anymore and keep on convincing her that if ever there are ghosts (I haven't seen one and I hope I won't), they are in other places and our house is ghost-free.   I hope she will overcome her fears of ghost as soon as possible.