What Was it That Pulled My Shoulder?

I wasn't sure if it was a ghost or not, and I have no idea what it was. But that afternoon, because I have relatives who came over for a visit bringing their children along, the house was so noisy. I couldn't concentrate to do my homework, so I went up to my room locking the door behind me. I was sure no one was in the house when I was there. I sat facing the window quietly doing my homework when I felt a hand pulled me backwards. I was sitting on a baby chair about one feet high. If I didn't hold on to the table, I would of fall flat on the floor. I was so scared that I ran out of my room and didn't return until my sister came up stairs with me. Well, as long as I know of, this have never happened to me before. I told my friends, and they said that it could have been my imagination, but I don't believe that there are such imagination that can pull a person backward like that. My Grandma had told me sometimes when she was sleeping, she was woke by someone, or something, that! was constantly pulling on her toes. I have no clue why such things had happened, my home was brand new built when my family moved in and had had no mysterious past. Well, my Grandpa died about month or so, but I have no idea why he would come back and haunt us, my family was sure that he had no unfinished business or messages to deliver.

Well, it didn't really change my life except for it gave my family the creeps, but I had no problem with it.