Membership record with same name but not living in our ward

Our ward has two individuals on record with the same name and same address, but only one of them actually lives in our ward. They have different membership record numbers and different spouses. No one knows the second individual nor how we ended up with his records but we have had them since long before I was called as a clerk. His contact information is clearly wrong and I don't know what to do with his records.

How about the other information such as Birth Date and parents information. If they are the same you may have a duplicate record with incorrect spouse information, or it could be that the spouse information is a prior spouse.

The two individuals are different people, with different birthdays (although within two years of each other), different parents, different spouses, different membership numbers, etc. The only thing they have in common is first name, last name, and address. They do even have different middle names. The bishopric has talked to the correct individual who does live in our ward at that address, but no one knows where this other individual's records came from. It sounds like it has been this way for a year or possibly longer. I'm relatively new in the ward and new in this calling. No one in our ward has any idea what to do with this individual.

Once you have followed the 9 steps to finding members provided in MLS and in the wiki article Locating members, the member can be moved out to address unknown. But it is good to provide some additional information in the "Contact Information" text box as to the similarity to the two individuals and that the one that resides in your ward is known while the other is unknown.