I have no choice but to believe because I saw one in my apartment a few years ago. Here's what I posted about it in another ghost thread:
Several years ago I was standing in my bathroom, primping in the mirror. Suddenly, through the mirror, I saw a man standing in my hallway just looking at me. I didn’t turn around to look at him directly and I wasn’t frightened (much to my surprise). He wasn’t “transparent” like I imagine a ghost would be. I wondered later if he was actually a Jinn. He had salt and pepper hair, was either a light skinned Black man or a tanned White man. He had on a blue, black and white plaid shirt and seemed rather short. About maybe 45 seconds to a minute later he seemed to just float sideways into our studio room. I didn’t recognize him and never saw him again. Being a “skeptical believer” I questioned what I saw. But after relaying the story to a few friends in different conversations, they all said that I gave too much detail to have imagined it.
I also have a friend who has a resident ghost in her house. She's been telling me about it for years. She said her son used to be afraid to go down there because there was a ghost but for a long time she didn't believe him. Then she finally saw it herself. Years later, one day while we were on the phone and she went "Oh sh*t!" I asked what was wrong and she said she just saw "Tophat", a name she and her son had given him, go into her house. From where she stood next to her car in her driveway, someone would have to squeeze by her to get up the steps to her front door. She sounded scared so I told her to go in the house and say "Que pasa amigo...what's happenin'?" It made her laugh. When she went in, she didn't see him. But a few weeks before that sighting, she said a friend who was helping her clean out her basement came and told her he saw a man in a top hat down there. She had never told him about the ghost, let alone it's nickname.
My ex boyfriend, a Jamaican, who used to ridicule people who believe in "Duppies" (ghosts) had gotten married but we remained friends. I hadn't heard from him in quite awhile and was surprised when he called me to ask a question about ghosts. He said he went into his young daughter's room one night and saw an "old woman" sitting on her bed. It scared him to death. I told him what I thought he should do...I forgot the details now...this was decades ago....and he never called back so maybe it worked. At the time he and his family lived in an old house.
I also know other reliable people, who's stories I absolutely believe, that have seen them.
@feywon