If you get a credit report direct from one of the major credit reporting agencies they should provide you with an address. If you can't find an address, then you are going to have to use the report number to call in the credit reporting agency to ask them to provide you with the address.
He can dispute no knowledge of account, for them to please remove.
Also want to ask you what state you are from, the debt might have expired the statute of limitations. Meaning if it went to court it could be thrown out due to being time barred.
http://www.carreonandassociates.com/...es/statute.htm