Official ballots shall be prepared by the certified agency and mailed by first-class mail to the last known address of all persons known by the certified agency to be eligible to vote. As announced in the public notice, said ballots shall be made available for a period of not less than 10 days, to those who are eligible to vote in said referendum and did not receive a ballot by mail.
Before any person shall receive an official ballot, he shall furnish such proof as the certified agency may require of his eligibility to vote in said referendum. The certified agency shall keep a list of those persons who receive official ballots. No person may receive more than one official ballot unless he satisfies the certified agency that his ballot has been lost or destroyed.
No votes shall be counted which are not on official ballots. To be eligible to be counted, ballots must be received by the certified agency at the place and by the deadline previously announced in the public notice of said referendum.
N.C. Gen. Stat. § 106-557.1