S.C. Code § 7-13-740
There must be provided at each polling precinct at least one booth. At least one booth must be provided for each two hundred and fifty registered electors or a major fraction thereof of the precinct. The booths must be made of wood, sheet metal, or other suitable substance; must not be less than thirty-two inches wide, thirty-two inches deep, and six feet six inches high; must have a curtain hanging from the top in front to within three feet of the floor; and must have a suitable shelf on which the voter can prepare his ballot. In primary, general, and special elections, the booths must be provided by the board of voter registration and elections. Only one voter shall be allowed to enter a booth at a time, and no one except as provided herein is allowed to speak to a voter while in the booth preparing his ballot.
S.C. Code § 7-13-740