I don't remember how old I was exactly when I first felt "not alone" in the basement of my parents' house. I was probably in the 10-11 age range when I would get the feeling of not being alone. Everyday I would come home from school and watch Nickelodeon on our basic cable TV in the basement. The house was built in the mid 80's, so it wasn't old/victorian/or even creepy at all. It was just... You know, a house. I would generally watch TV and play with my legos or draw in my sketch book or something to keep myself occupied.
Eventually though, I started getting the feeling sometimes that I was not alone down in the basement, and sometimes I would even see something out of my peripheral vision going down the hall to my right.
I would like to point out that I wasn't watching anything on TV that would weird me out and make my mind play tricks on me. I was usually watching Doug, or Darkwing Duck, or some other ridiculously awesome program when I would just see something jet through the hallway. I'd turn my head (of course) but nothing was there. Honestly, I wasn't really all THAT weirded out by it because I had quite the imagination, so I just blamed it on that. Not to say I didn't believe in ghosts - my favorite movie in the world was (and still is) Ghostbusters, and I've always loved the occult because of it.
This is where the story finally got me. One day I was in the upstairs bathroom brushing my teeth or sneaking a delicious Flintstone vitamin or something when I felt a hand touch my shoulder. I looked up into the mirror (because I was facing that direction) and saw a figure behind me... Looked like a guy, but I wasn't checking for chest hair, so I could be wrong. Naturally, I fled from the scene uttering obscenities at the world as I burst out the front door and into the road outside. I don't remember how long I stayed outside before I finally went spelunking back into my home, but I would venture a guess that it was a while.
On another note, my mother (who is REALLY into ghost stories / hauntings) claimed that she was home one day while I was at school and heard the door open and close downstairs. She assumed I was home early from school and yelled my name down over the banister towards the bottom of the stairs. No one answered... Especially not me because I was at school. Mom then called my sister's name... again, no answer. At this point, she went downstairs to investigate and found nothing. No matter what happened there, Mom believes that a ghost was up to shenanigans in our house.
Because we're adventurous, and mildly stupid, Mom and I decided to take the ghost thing kind of seriously and looked into the housing development's history. We found 2 things:
1. The housing development was more or less brand new.
2. The development was built over old farm land, and as it turns out, about 2 courts away there used to be a cemetery for the farmer's family. Our neighbors/friends lived in that court and also claimed they'd hear the basement rocking chair in their home make noises in the night.
Well, that's all I got. It's all true and it happened back when I was a kid (I'm 26 now). It wasn't evil or anything... Just an experience or two.
Love peace and bacon grease!