The IRS is contacting your because their records indicate there is an outstanding refund check issued to the taxpayer - the refund check is outdated and no longer valid. If you still have the check, destroy it and contact the IRS to receive a new refund check. If the check is lost contact the IRS at the number on the notice to verify your information and receive a new refund check.
Note: If you filed a joint return, the IRS will send a copy to each spouse that contains the same information.
Sections of the Notice:
Sample CP 32A: