This story happened about 2 to 3 years ago to a friend of mine and two other people she knows.
We'll call her Sarah, and her friends were John and David. Anyway, where they live there was a house which was supposed to be haunted. One day they went into it for some reason or another. Inside, the house seemed normal to Sarah and John, but David started to freak out. He said he could see a girl. He shouted at them to help her. I think his exact words were "Help her, they're going to kill her, Help her!" They followed him out into the back garden where he ran to a small tree in the corner. He started shouting again to get them to help her. He said they were going to hang her. He fell to his knees and started crying that she was dying. Sarah and John had to bring him out of the house before he did something crazy.
The next day Sarah received a letter from David. All it had written on it was: "It's your Fault she died. Why didn't you let me save her!". The next day John and Sarah found out that David had died in hospital during the night.
This story was true down to the very last word. I found it to be one of the strangest stories ever because it is true.