Shadow Child

Since last year, I've been seeing a shadow of a boy. I have only seen him a couple time before last night, but last night was the weirdest.

Even though it was only recently I became interested in ghost, demons, angels, things like that this hasn't been the first time he walked in front of me. I'm only twelve so I got startled easily - even though in my group of friends I'm the one calming down the scared ones, normally nothing scares me easily - he normally just walks by my TV, but last night he ran by, I had a violent chill, and felt like someone was watching me the whole night, plus it felt colder than normal. I don't know why but I was hyper for the rest of the night, and just a moment ago I felt like I was going to pass out. A couple days ago I've been feeling sick ((My throat hurt - even enough to make me cry)) but it started to go away. I've only seen him in my room, does that mean he wants only my attention? What can I do? People say I look a lot like my grandmother ((Who is dead)), does he think I'm her?

I don't know if he's good or bad, I told my mom, she said nobody has died here before - my great-grandfather even built the house. The ghost/shadow seems nice, if he wanted to hurt me he would of already, right...? My friend and I were talking about it, we thought he was connected with my grandmother, and when I asked my grandpa he had a smile on his face. I'm confused...

Advice please.