Scary Sleepover Prank
I just thought of this prank. It will only work if you have a back door and a friend with good acting skills. Make sure that you tell your parents what you are going to do. Have your friend bring a hoodie.
Before scary story telling, secretly tell your friend to put on the hoodie.Have your friend say they have to go to the bathroom during story telling. They will actually go outside the front door. When he/she is at the front door, she will have to knock. Bring everyone to answer the door,while your friend runs to the back door and runs in and act like shes posessed. (Note that his/her hood is up). Have him/her chase everyone.