EVIL PRESENCE IN MY BROTHERS HOUSE!!!!

My brother's live in Fairmont during college with four other strong Christians in one big house. I guess strange things started happening the about three weeks after they all moved in. One incident occured to one of my brothers when he was home alone. He was getting ready to take a shower and he locked all the doors and windows and went in to take a shower. When he got out, he felt a breeze through the house. He walked around and every window and door in the house was wide open. He searched around and found no one in the house. About two years later, after many many other weird occurances, I went to stay at the house for spring break. The second night I was there, my two brothers, their friend and I were all in the upstairs living room watching tv. No one else was in the house. We all heard a door slam shut and open then slam shut again in the basement. My brother and I went to check it out. When we got downstairs, the door to the basement living room door was shu! t, cracked, and locked from the inside. About two day's later, I was home alone while everyone else was in class. I was watching tv upstairs when I heard someone or something moving around downstairs. I went down to check it out. I got about half way down the stairs and the door opened then shut. I hurried up and got to the door to see if anyone was in the house. I looked around everywhere, but found no one. About a week later, after everyone was tired of the strange happenings, everyone got into a circle and prayed that if anything evil was in the house that it would go away. Nothing strange has happened in the house since then.