Usually they just say their previious deal was a roommate situation and or the place burned down or was sold and the owner moved out of state and sadly, their contact info is unknown. 

On top of that, many people become "accidental" landlords when they inherit property or can't sell a primary for some reason when they need to move.On top of that, there is a large, unknown, contingent of "investors" who are wholesalers, agents, or otherwise involved in the real estate industry but do not actually own property in a meaningful way. 

Yeah, but this is rough not to answer unknown calls if you were a real estate broker like I am in Indianapolis. 

But, I would never agree to anything unknown without a safety net.

I can see mail delivered on the porch that is addressed "to unknown heirs of (the deceased individual)."

(Source unknown).You've got better things to do. 

Because they are unknown or high risk and banks know it's a waste of time.

And when I mention take fear out it is more the fear of the unknown which sounds based on your comment you have which is very normal.

The one unknown that always pops up is the number of sheets of plywood underlayment that the roofer will need to replace.

Probably depends on the city and the HOA.I would also think you open yourself to some liability for theft and assault and all kinds of other issues when you get unrelated and unknown people living in the same house.I'm sure plenty of us have done it at one time or another and I'm sure there are plenty of people who do it....but I think it is tricky.