Selling it and downsizing might be a safer and better option. Sounds more daunting, I know. Didn't look forward to uprooting and moving to an entire new community when my wife's mobility issue pretty much dictated we needed to and I still miss the old neighborhood. But exploring new surroundings is fun as well. If you do decide on taking in a roomer I would read Talking To Strangers by Malcolm Gladwell, which is an eye-opening and scary look at how bad we are in judging people we don't know -- and it seems it is because of the way humans are wired to judge strangers -- and how those who should be best at it (law enforcement, judges, intelligence services) actually are the worst at it. Then if you still want to take in a roomer I would look to some screening/placement service (colleges needing housing for students, nonprofits serving those in need) which have done some background investigation on candidates for referral.
