Midnight Mystery

I was lying in bed late the other night going through my usual nightly routine of looking up comedians on you tube when lo and behold, there was a knock at the door. I ignored it, being in a pajamad and exhausted state. But then, the doorbell rang which woke up the dog who began barking which woke up the roommate who poked her head into the hall looking as befuddled and disgruntled as I felt. After ascertaining that neither of us was expecting company we agreed NOT to answer the door. Mystery Creepy Person must have heard us whispering though because they began banging insistently on the door. My karate expert housemate braved a look through the peep hole at this point and reported back that there was no one there. We returned to our respective beds thoroughly creeped out for a night of restless sleep. Any helpful or creative theories on what might have occurred that could help ease my mind?