Ghosts are definitely real. I've had tons of experiences, and my house is pretty active.
For instance, just last night, I had a ceramic bowl in my bathroom for my dogs to drink out of, and while we were laying in bed, the bowl managed to go from the corner by the sink to the middle of the floor and broke into 3 pieces. The dogs were in the bedroom with us, and this bowl is/was thick and heavy. So it wasn't the dog moving it and picking it up and dropping it. But the bowl full of water definitely moved, dropped, and broke. Scared the hell out of me when it happened.
Last week, we were getting ready to leave the house and the radio turned on. I turned it off and walked to the door, and it came back on. I turned around, went back and turned it off again. Walked to the door and it came back on. So I said, "Ok guys, we have to get going, we won't be gone too long, so let's stop with the games for now, please". I turned it back off, and it didn't come back on. It was when we came back home that the bathroom light was on. So the wife went and turned it off. I went back out to get more groceries and when I came back in, the light was on again. I asked her why she turned the light back on, and she said she didn't. So I turned it off and we both went out to get the rest of the groceries... when we came back in, it was on again. So I asked them to stop playing with the lights as I turned it off, and it stayed off.
A few months ago, the wife and I were sitting on the couch, and my dogs wanted to go out. So I got up and walked over to the sliding glass door and let them out. I have a dvd rack about 6 feet away from the door, and I walked right in front of it. Let the dogs out, came back and sat down and continued to watch tv with the woman, who was still sitting on the couch. About 5 minutes later I looked over at the door to see if the dogs were sitting there waiting to come in, and there in the middle of the floor was a dvd case standing on edge, about 2 feet in front of the dvd rack. Neither the woman nor I had left the couch. I told her to look at what "our friends" did and she was like wtf?
These are just a few of the latest things that have happened in my house. I've heard them, seen them, and interacted with them, so I'm saying yes, they are real.