Accepting a payment, usually in the sum of $3,000 to $5,000, to allow someone to use your name and credit record to attain a mortgage on a property is fraud, and could result in jail time.
Regardless of how well one might feel they know a potential buyer, the truth of the matter is that these transactions are illegal. Participants could end up with heavy fines, a prison stay, and the saddling of a mortgage on a property they never intended to dwell in or own.