Use your gross dorm room to scare your crazy roommate
Dorms can be pretty terrifying — scuzzy bathrooms, cinder block walls, a wack job roommate — I'm getting scared just thinking about it. Might as well use your petrified dorm room for good and make a haunted house out of it to creep the people on your floor out. Turn off the lights and follow these steps to have your crazy roommate run out screaming in no time.
Get a fake a smoke machine if you have access to one. There is just something about smoke blowing in the pitch black darkness that makes people get a case of the goosebumps. Make sure no one you invite in has asthma though. The objective is to not have someone go to Robert Wood Johnson.
Try to persuade someone in your dorm to dress up as something horrifying to pop out and scare people. One time at a haunted maze, a man in a Freddy Krueger mask popped out and grabbed my arm. Of course I freaked out to the max and almost decked him right in the eye. To avoid the person you "hire" from getting a black eye, instruct them not to grab the person. Again, we want to avoid any emergency room visits. Haunted houses can clearly be pretty dangerous.
Sounds from hell
Play that eerie piano theme song from the movie "Halloween" for your haunted dorm. People will either think this haunted house is a total joke or actually good — let's go with the second one.