I just purchased a new home and I have noticed that in my bedroom after I retire and shut the door.. it sounds like someone is trying to open the door but couldn't.. and yesterday when I was finishing up with my shower in the bathroom this time.. the door shook like someone was hurrying to open it as if there was some sort of problem or trouble.. but when I opened the door.. there was no one there.. no one home but me.. has anyone else been through this.. what help can you offer me?