I wouldn’t do it. Besides the risk of foreclosure, he’s probably got no idea what it means to be a landlord. Being a landlord (landlording?) is a business. Done properly, it’s not just “passive income”. He’s probably going to see you as someone to keep the squatters out of the place and cover part of the mortgage until the market turns. He’s not going to see you as someone that he has a responsibility to. I rented from an investor once, but never again. She cut every corner possible on repairs, raised the rent with gusto every chance she got, stuck us with inflated water bills, and then chiseled us out of the cleaning deposit when we finally bailed. From now on, I’m sticking with professional property owners/managers.