N.C. Gen. Stat. § 74C-21

(1) No law enforcement officer of the United States, this State, any other state, or any political subdivision of a state shall be licensed as a private detective or security guard and patrol licensee under this Chapter.

(2) An off-duty law enforcement officer may be employed during his off-duty hours by a licensed security guard and patrol company on an employer-employee basis. An off-duty law enforcement officer shall not wear his police officer's uniform or use the police equipment while working for a security guard and patrol company.

(3) A law enforcement officer may provide security guard and patrol services on an individual employer-employee basis to a person, firm, association, or corporation that is not engaged in a security guard and patrol profession.