The first time happened to me when I was about ten. I was with my sister and our friend from next door, they were the same age as me. I remember we were all playing a board game in our basement when my dad - the only grown up in the house - told us he was going to leave but wouldn't be gone long. Well, we weren't concerned about it so he left.
About ten to fifteen minutes later, we all hear footsteps above us as well as the water in our kitchen being turned on and assumed it was my dad, even though we hadn't heard his truck pull in the driveway. So, I go upstairs to see if it was my dad and there's no one up there and no water turned on. And after I'd been up there for a few seconds, I got the distinct feeling of being watched, even though I couldn't see anyone and, at the time, we had no pets. I immediately went back down to the basement and told my sister and friend what had happened and we stayed in the basement until we saw my dad's truck pull into the driveway.
The second story isn't really an experience as specific as the first one. It's just feelings I get, mostly in basements. I do not like being in most basements alone because I don't think I am alone in them, even if it is someone - or someones - that I can't see.
While I can stand being in most basements alone, my aunt's basement scares me. Sometimes when she goes on vacation I go up to her house to watch her dogs for her. Well, the first few times I went up there, I didn't have a laptop of my own, so I was allowed to use the one in the basement. Whenever I was down there, I'd have every light on and the TV playing or I couldn't stay down there. I'm always on edge in there, like there's something down there that doesn't like me. After I got a laptop, I stayed upstairs when I went to stay and the basement door would always stay closed. I'd only go down there if I absolutely had to and even then, I'd only stay for a minute at the most. And even though I'd shut the basement door behind me, there was a few times that I'd notice it was open.
The third story isn't as scary - to me - as the other two. And it's more recent; it happened about five months ago. My sister and I live with my aunt - not the one in the second story - and I live on the top floor of her house. Well, I have a tall mirror leaning up against the wall in front of my bed. The bottom gets really dusty and there's a few times that I'd notice streaks in the dust, like they were made by a child and I just assumed it was my niece. But then one morning I woke up and there was a child's handprint in the dust. It was too small to be my niece's but I asked her about it and she said she hadn't done it. I haven't seen anything more than the smears and handprint but it makes me wonder if there's a child ghost around.