This happened when I was about 12. My family and I were on vacation in Black Hills, South Dakota during the 4th of July weekend. The hotel we were staying in consisted of many small cabins in a circle around the main office. When my parents were checking in, the front desk clerk started talking about the cabin he had assigned us.
He told us that our cabin was haunted by a person who had stayed there 25 years before. The person had killed himself in the bathroom by slitting his wrists! My parents just laughed at him and grabbed my sister's and my hands and just walked away.
That night, my parents were outside our cabin, enjoying the fresh summer air.
My sister and I were tucked into one of the beds. I was still thinking about what the clerk said about our cabin when I heard a high-pitched whistle coming from the small bathroom in the corner. My sister jerked and sat up in bed. "What was that?" she whispered. "I didn't hear anything," I said, trying to tell myself that we were imagining things and were scared because of what the guy told us.
My sister laid back down beside me and right when she did that, there was another high-pitched whistle...coming from the bathroom! This time, we both sprang up in bed. Our parents had kept a small lamp on on the other side of the room, and from the glow of the lamb, we looked toward the bathroom and saw a hand gripped the doorjamb. The hand was covered in blood!
My sister and I jumped up and ran outside to our parents, still wearing our pajamas. Our parents tried to convince us that we just had a bad dream and to go back to sleep, but we refused to go back into that room. Finally, our parents got tired of trying to get us back to bed, so they went in and got our stuff and put it into the car. They tried to tell us that they didn't see anything, but we wouldn't listen to them. We got out of there quickly and drove around until we found another hotel. Fortunately, this one didn't have any stories about it being haunted.