N.C. Gen. Stat. § 8-79
The sheriff of the county where the witness may be shall execute all such subpoenas, and make due return thereof before the commissioner, or other person, before whom the witness is to appear, in the same manner, and under the same penalties, as in case of process of a like kind returnable to court; and when the witness shall be subpoenaed five days before the time of his required attendance, and shall fail to appear according to the subpoena and give evidence, the default shall be noted by the commissioner, arbitrator, or other person aforesaid; and in case the default be made before a commissioner acting under authority from courts without the State, the defaulting witness shall forfeit and pay to the party at whose instance he may be subpoenaed fifty dollars, and on the trial for such penalty the subpoena issued by the commissioner, or other person, as aforesaid, with the indorsement thereon of due service by the officer serving the same, together with the default noted as aforesaid and indorsed on the subpoena, shall be prima facie evidence of the forfeiture, and sufficient to entitle the plaintiff to judgment for the same, unless the witness may show his incapacity to have attended.
N.C. Gen. Stat. § 8-79