I knew a retired couple who did this. They lived off their SS. They didn’t have utilities to pay as it was all included. And they didn’t have to make repairs, there was a maintenance man for that. They just had their front room as the office, with a counter and a bell like you see in the movies. They did the clerical stuff, collecting rent, handling noise disputes. It can be a sweet deal if everyone gets along and no one is abusing the situation.