Are ghosts real?

Are they? Up until about five years ago I didn't believe in ghosts. It seemed propostourious that such a thing could exist, and then we moved into my grandfather's old house. One of the first instances that led me to believe in ghosts I was sitting in my basement with two of my friends at around midnight, we were just chatting when all of a sudden we heard the floorboards creak above us. Assuming it was my mom coming down to say goodnight I went up to the first floor. When I got up there the lights were all off and no one was awake. Somewhat confused I went back down and continued to confabulate with my friends. About 5 minutes later I hear yet another crash from upstairs. Starting to get concerned that maybe there was an animal or burglar upstairs, I grab a my grandpa’s baseball bat, and head upstairs to investigate. I turned on all the lights, checked the entire first and second floor; both parents still sound asleep, nothing seemed out of place at first. After I started to descend back to the first floor once I had checked the rooms upstairs I witnessed something quite out of the ordinary. Before my own two eyes a 8x10 picture of my grandpa fell onto our couch in the living room. While this might not sound like a valid reason to believe in ghosts, I left out one key detail. The wall where the picture had previously been was on the most northern wall in our house and the couch was resting against the most southern wall, meaning the picture flew some thirty odd feet across the entire width of our house. Was it a ghost or maybe it just had to do with the EL being near us, I may never know.