He was mid 20's, 5'-8"-ish, white guy. Clean enough to not seem homeless, dirty enough to seem not to have been home for a day or two. Very average build.
And JosephCPR - I kept in mind that he may be someone who needed help instead of someone who posed a threat. But I also kept in mind that he could pose a threat as well. I don't assume someone needs to be shot right off the bat. But I do believe in being ready for anything...or at least as many possibilities as I can think of. This guy was completely wasted, he really didn't seem to be surprised when I told him he had the wrong house, and when I ask for information from him, he refused to give it. And I wasn't asking for his credit card number, just who he was looking for and if he had an address for them or a phone number or even a street name. He said he was lost and then said a street name and said he knew what direction that street was in. He did give me names twice, but they were different names both times and he seemed to be unsure of them. I suspect strongly that there was something other than a simple wrong house going on with this guy. At the point where he refused any help, but still could not give me a coherent story, and then stood a hundred and fifty yards off and stared at the house for far too long, I decided that concentrating on safety was what was prudent.