Creepy Little Boy

Hi there, I guess I should start out by saying this...I'm a big wuss when it comes to ghosts or spirits or shadow people or whatever you want to call them. I'm the type of person that goes on a ghost hunt and is sweating bullets the entire time while my eyes are shut or I'm staring at the ground and trying to convince myself that there is a logical non-paranormal excuse to cause whatever just happened. I've been seeing stuff like that ever since I can remember but as I've gotten older I've found that they seem more real and I think they just freak me out more because I know what they are, where as when I was little I was told it was just my over active imagination so I just thought that some were my imaginary friends while others were my imaginary bullies (those were the mean ones). But anyways, I was wondering if anyone knows how to basically get it under control, for me it's gotten a bit out of hand with one thing mainly. There's this kid that I keep seeing, and when I talked to the people that I live with they didn't really care at all because apparently that sort of thing is normal for them and they've just come to accept it all. But for me I see it as getting out of hand because I keep seeing this little boy with black hair and he looks alot like one of the adopted kids in the house, so every time I see him running around I think he's the adopted kid and I chase after him since he's not supposed to be running around upstairs by himself. Sometimes he'll turn around and I just get this really bad feeling coming from him and it creeps me right out. Other times I'll hear a knocking on my bedroom door so I'll check and I see him running down the hall and then disappear either at the end of the hall or he'll go into a room and disappear before I get there. And lately the kid seems to be popping out of no where, I'll look at the couch and then turn around and look at the couch agani and he'll be sitting there staring at me. Or like many times, I'll be holding something and he catches me off guard and I end up dropping whatever I'm holding when I see him out of no where, and then he disappears almost as quickly as he showed up.
Does anyone know how to either how I can get the kid to stop showing up everywhere or anything? Really anything would be helpful. I've tried talking with the people I live with but they don't really want to talk about it since they live with all that stuff every day of their lives.
I don't know, maybe I just need to get used to it or somethnig. Because I was always told that I just had an over active imagination and even when my sisters would see the same thing I was blamed for influencing them. So it's a bit weird to me when I say I saw something and just about everyone in the house tells me that they've seen it as well multiple times and I'm the only one getting freaked out by it.
Sorry for this being so long, I tend to ramble on a bit. But any help, advice, anything would be wonerful.