Oh, I most definitely believe in ghosts, having lived in a haunted house for 8 years. I also have a spirit/spirits here in this location and have had my behind grabbed and "something" screamed in my ear plus you can hear conversations spoken really low at night.
In our previous house I turned and saw a lady in a peasant dress with very long hair and folders in her hand. She was standing over my husband's side of the bed and when I gasped she disappeared but not before turning and looking at me. When I described her to my DH, he thinks it was his grandmother who had died a few weeks earlier.
My grandmother and I had a deal, if she went first she would send me a sign and I would do likewise. At 3:30 one morning the alarm went off, it wasn't set to that time and wasn't active. 15 minutes later I got the call that she had passed away at the hospital. I thanked her for letting me know there is something more out there.