Have you ever "encountered" an experience with one or a few? I believe in them. I certainly do, no doubt about it.
In my house, I experienced weird/strange things happening. We had three ghosts in our house two years ago. One ghost was a neighbor who passed away from an heart attack, and he spent his time in our house, spent his time teasing us and the dogs. When he was alive, he absolutely did not like the dogs. He found them annoying. He would tease Rosie and one time, I saw this happen, she yelped and peed right on the middle of the kitchen floor, RIGHT AFTER she came from outside during the day. That was just crazy. You know how Anna used to escape so many times when we had no fence in our backyard, how we were so baffled about how she could get out of the yard, even if she had been checked if her rope was tied on her right? (Doggy trolley).. The ghost let her go, unleashed her, and had her run. This happened 3-4 times.. that was a crazy time.
The other two ghosts, they followed my dad home from work. They were wanting to find a place where there were a lot of energy held, and I guess, our house had a lot of energy, since I have two brothers, two dogs, and the parents. They were harmless to us, except the neighbor. They would play games on us, like misplace objects but they'd place it back eventually.
The neighbor, he taunted my brothers often. He hung out in my brothers' room - and this happened. When my brother got out of the shower, and he looked at me, and said "I felt someone hit me/slap me on the back with a hand." and he showed me the marks, and I didn't believe him. I told him, "Yeah right.. " but he said, he was serious.. he compared his hand size to the one on his back.. it was so freaky, there were finger prints, like he grabbed onto his back with his fingers. That's how we knew, this ghost was just bad. All he did was to tease us.. He would turn on the tv, and we'd shut it off, and he'd turn it back in within 5 minutes. My brother felt him walk by, with a cold breeze in his room one time. Since I can't hear at night times, he managed a way to freak me out. He would set my alarm clock to go off at the wrong time of the night.. One night, it went off at 3am, and the alarm was OFF. I shut it off, wasn't thinking, I was dead-tired, then it went off again in 5 minutes. I got a little concerned, but ignored it again, and shut it off, actually I unplugged it, and guess what? It WENT OFF FOR THE 3RD TIME.. after few minutes, and I just freaked out, and spent the rest of the night in my parents' bed.
You ask, how do I know all this? How did I know who the ghosts were? We had a ghost lady come over, and she spoke to my parents. We have a few pictures that showed orbs, and they were definitely in the picture(s). She spoke to my mom over the phone before she came over, and she TOLD her where the ghosts were, and what they were doing right now at the moment. She told mom that the neighbor was sitting on the stairs, looking out at the front yard. The other ghost was in the kitchen with my mom, just sitting on the counter, watching. The third ghost was in my brother's room, leaning onto a counter and looking out the window.
This whole thing is freaky, so that made me believe that there are REALLY ghosts out there, good & bad.