How do i contact a ghost in my house?

well my brother's room has had a lott of things happen, he has been hugged and watched, but when he had his friend around she got scratched in 2 places (3 scratch marks like nails), the other night all the screws came out of the door, i mean the handle also last night i something pushed me to one side of my bed and basically shoved me. how do i get in contact without hurting me or anyone else?