Yesterday while asleep..suddenly I saw my door close by itself and two hands (could feel the sensation very strongly) grabbing my hands..The moment I screamed..everything was normal. I am sure you guys are thinking it is a dream but I strongly felt the sensation. Two incidents like this happened in my past. When I was in my 11th grade..when I rolled over in my sleep....a very horrible disfigured person was lying next to me and when I screamed..parents came rushing into my room.Even my dad mentioned I remember vaguely " Is there a ghost in this house"? Again after coming to US, In 2005, it was around 8 in the morning..I felt few invisible figures groping my neck and holding me very tight and I felt breathing.The sensation was too much and I felt crushed and finally I gathered strength and everything looked normal. Do spirits exists or has this something to do with some Alpha,thetha,beta levels..something I researched about.. Have you guys experienced anything like the above?