(This probably won't sound like a nightmare but it was)I walked into my bedroom and yet it was my bedroom from my childhood home and there was a young ghostly girl standing with her back to me, she didn't turn around but she giggled and it was a very childlike giggle and I stayed standing in the doorway and the girl turned around and looked at me and giggled again before disappearing. I then walked to my bed and got into bed and my sister called to say goodnight and then the ghost girl came back and mockingly said goodnight to me. I felt very unnerved by her and asked what she wanted. She told me she wanted to leave but didn't know how to and when I told her I would try and help her she disappeared again.Then the next thing I remember is that it was a few days later and she came back and was angry that I hadn't helped her. I told her I was sorry and that I didn't know how to help her and then she turned herself into a cat, jumped on my bed, bit me and then jumped down before turning back into a girl again. I knew she was very angry and I started to cry and said I was sorry. She glared at me and opened her mouth to say something but I woke up before she could speak