S.C. Code Ann. § 53-1-40

On the first day of the week, commonly called Sunday, it shall be unlawful for any person to engage in worldly work, labor, business of his ordinary calling or the selling or offering to sell, publicly or privately or by telephone, at retail or at wholesale to the consumer any goods, wares or merchandise or to employ others to engage in work, labor, business or selling or offering to sell any goods, wares or merchandise, excepting work of necessity or charity. Provided, that in Charleston County the foregoing shall not apply to any person who conscientiously believes, because of his religion, that the seventh day of the week ought to be observed as the Sabbath and who actually refrains from secular business or labor on that day.