This is entirely real and has still shocked me to this very day. (This might be a bit short, but it really happened.)
I need to explain a few things before I can continue to the real ghost encounter. My house is a bit echoey, and I able to hear anyone moving up and down the stairs from my room. I can also see their shadow underneath the door when they approach it.
Anyway I think it was around 7:00-8:00 pm. I know it was night-time. I was on my iPad just Google searching a few things. I have forgotten because I never got to write my experience down, so this is from memory. I heard my mom come down and go to her room (because our rooms are in the basement.)
So after she went back upstairs I was alone for a few minutes. Or so I thought. Not very long from when I heard my mother's footsteps go upstairs, I heard a loud knocking on the wooden door I have. It was knocking, I mean, smacking the door multiple times. I saw no shadow and I only heard the loud knocking. I was afraid to go out there, so I waited. I heard no footsteps either, which I expected to hear if it was anyone messing with me, but the only people in my house is me and my parents, and my parents were too busy watching a movie.
I finally went out the door, no one was there. It may sound cliche but it's what happened. The rooms were closed and dark, indicating that no one was in them or someone was asleep, but I heard no snoring. I asked when I got upstairs if anyone knocked on my door and my parents both said no.
I am being very serious. I want know what that was, and why it happened. Anyone have any ideas, it's still creeping me out.