If a person cosigned for your house then died and you are about to sell the house do any of the family members of the deceased have any rights to the home that you are selling?

If the deceased person only co-signed, that is, lent his credit standing to you so that you would be approved, then the family has no stake in the property. All the co-signer did was ensure that if you defaulted, he would be financially responsible. He never owned the house, so no relative can make a claim against it.