Need HELP. Does this purchase make sense?

[Ryan St Pierre]

A family member of mine make some bad financial decisions several years ago and tried to keep it quiet by borrowing money at terrible interest rates from quick loan companies. They have a single family home that needs some fixing up. 

I was thinking that if I could get a good deal (which I'm sure I could given the circumstances) that it may be mutually beneficial for me to buy the home. They could wipe their debt clear and immediately begin renting from me. They have 2 older children living at home. My idea is to hold and rent until the kids move out (approx. 5 years) fix it up and increase rent. At that time hopefully they will be back on their feet and either purchase another home or pay the increased rent. Dealing with family scares me a bit but not too much as I would be up front about the plan.

Does this sound like a good investment? Also I have 2 options, I could refi my house to pay for it or try to get a second mortgage. I was leaning this way as I understand that I can write off the interest on a rental. Also after fixing up the place I could try to refi the rental and use that money to pay off my primary residence. Numbers are irrelevant for now as I will crunch those if I decide it is a good idea. 

Any suggestions would be greatly appreciated. Thanks in advance.