If you happened to side with anyone other than Mr. House, you would know that he is very much real. While he lets the player believe that he is some sort of AI-powered supercomputer, Mr House is, in fact, still living in a crypt below the Lucky 38, being artificially kept alive in a super high tech cryo-chamber. So if you want to see the rather disturbing and pathetic human form of Mr. House, simply hack his terminal in the Lucky 38 and go see for yourself. Just don't expect the Securitrons to take too kindly to it.