What to do about a ghost in our dorm room?

Okay, so my friend and I live in a dorm room together at college. Since the beginning of the year, our door would slam (very loudly) shut and sometimes open up. We just blamed it on the fact that we had our window open, but it's happened since our windows been closed, and it will happen to our main door when it is wide open and we're sitting out in the common area.
My friend and I would joke about ghosts and one night we did a little research on our campus and found that there are a couple places that are 'haunted' and one is near by. A girl froze to death outside and people have seen her in the tunnels that connect our dorms late at night.
Anyways, the other night my friend went to the bathroom and left her iPhone on her desk. When she came back, there was a message typed but not sent on her phone. It said "F*** you all." I didn't type it and my friend didn't either. That's not something she ever really types so its not a quick message or something copied.
I wouldn't say the ghost is mean, but giving us that message isn't the friendliest, I guess haha. We don't mind if it's in here as long as it's friendly, but what should we do? We want to find out more so do we try talking to it? Or what? Any help is appreciated!

The answer to your problem is a Genuine Hasbro Ouija. In fact a Genuine Hasbro Ouija is as important to a University student than any text book. How the heck is an intelligent student going to learn if their dorm is haunted.
It's factory installed student dorm room specter sweeping meta-technolog, will send that profane poltergeist packing. The rude revenant was probably drunk when she froze to death. Unfortunately she'll stay drunk as she remains a ghost. How is a drunk ghost going to find the light anyway

The supposed spirits of the dead are demon spirits. Avoid the occult and spiritism and pray to God. Use God's name in your prayers. Prov 18:10; Psalm 83:18.

First, throw out any idea for solving these issues that are not logical. Ghosts are not logical - there's no solid proof of the existence of spirits. Look at each individual occurrence, and figure out why it happened. If certain events show no reason for being connected (door slamming and mysterious text on a phone seem unrelated), don't assume that they are.

The door slam, for example. A dorm is a large building, with doors opening and closing internally and externally all of the time. It would be virtually impossible for you to determine the effects on the internal air pressure of the building. Two doors on the same floor opening or closing at the same time could slam your door, or it could do nothing at all - the system is too complex to analyze. Internal air pressure shutting the door is the most logical explanation. The solution is simple, buy a doorstop.

Just because an explanation isn't easy to come up with does not mean you should resort to thinking something paranormal is going on.