N.C. Gen. Stat. § 163-87
On the day of a primary or election, or during the hours for early voting under Part 5 of Article 14A of this Chapter, at the time a registered voter offers to vote in person, any other registered voter of the county may exercise the right of challenge, and when the voter does so may enter the voting enclosure to make the challenge, but the voter shall retire therefrom as soon as the challenge is heard.
On the day of a primary or election, or during the hours for early voting under Part 5 of Article 14A of this Chapter, any other registered voter of the county may challenge a person for one or more of the following reasons:
The chief judge, judge, or assistant appointed under G.S. 163-41, 163-42, or 163-166.35 may enter challenges under this section against voters in the precinct or at the early voting site for which appointed regardless of the place of residence of the chief judge, judge, or assistant.
If a person is challenged under this subsection, and the challenge is sustained under G.S. 163-85(c)(3), the voter may still transfer that voter's registration under G.S. 163-82.15(e) if eligible under that section, and the registration shall not be cancelled under G.S. 163-90.2(a) if the transfer is made. A person who has transferred that voter's registration under G.S. 163-82.15(e) may be challenged at the precinct to which the registration is being transferred.
N.C. Gen. Stat. § 163-87