<prompt> Human: My grandfather is planning on refinancing his home and asked if I could cosign. Im 21, still going to school, only work part time, and live with my mom. He cant ask any other family member because of their own financial complications. I wanna help family but Im nervous just thinking about it. I think he plans to rent it out and that adds more uncertainty for me. Its one of my first major financial decisions and any guidance would be appreciated.  <response>: It sounds like you know this is a bad idea. It is. At best it will make it difficult to buy your own home later on in life if you cosign. At worst you will be on the hook for the mortgage.If he needs a cosigner to refinance then his credit is bad andor he is carrying too much debt for the bank to consider giving him the loan by himself. 