Stationary Ghost Or Am I Seeing Things?

This is my first post on this site and there will be plenty more to follow as I have had many different experiences. Ever since I had my first experience at my grandparents' house (which I will explain in the future) I have been interested in the paranormal and everything involved with it. Although I refuse to use Ouija boards for obvious reasons. Let's begin with the most recent experience.

I live in Southend, a seaside town in Essex, England. I have lived in my house for 13 years (unlucky for some), but have only ever experienced activity there once, three weeks ago from today (24/10/2013).

Now, as you would probably have guessed by the title, the activity involves the stationary I keep on the desk in my room. Note, this includes bits like staplers, a staple remover, post-it notes, pens, etc, you get the idea! Anyway, I was doing some drawing, which is one of my many hobbies, and got called downstairs by my parents for dinner.

The upstairs landing of my house is as follows: as you come up the stairs, my room is right there, next to that is the spare room, where guests stay and where my parents keep their books and old bits. Next to that is the bathroom, followed by my parents' room, and then finally my brother's room, at the opposite end of the landing to mine.

Before heading downstairs, I closed my bedroom window and headed to the bathroom to use the toilet. When I came out of there, the landing was suddenly freezing cold (remember, I closed my bedroom window, and no other windows were open... I checked!) and I noticed my stapler was on the floor near my bed. I thought this was rather odd, as I left it on the desk near my laptop. So I picked it up, placed it in the middle of the desk (remember that!) with everything else and headed downstairs for dinner.

Afterwards, I made my way back upstairs and saw a streak of white go past my bedroom door and into the spare room! I stood on the stairs, wondering what it was... So I bravely ventured upstairs to see if I could find out what the white "mass" was and couldn't see anything.

This is the weirdest part... When I went back in my room, the stapler was not only back on the floor, but it was also open and there were staples everywhere! Now, anyone who owns a stapler will know that it takes some force to open the top so it would have taken something with a bit of strength to open it. (Remember, I had put the stapler away from the edge so there is no way it could have fallen off.)

Is this a ghost or a poltergeist? Is it trying to get my attention or is it just doing it for fun? At the moment, I am quite scared so would like to know what you all think!

Thank you for taking the time to read my story! I will take all comments and opinions into account and will answer any questions you may have.