In all cases where witnesses are required to attend the sessions of the commission they shall be notified by a summons issued and signed by the secretary of the commission, and bearing the seal of same, and mailed to them, or which shall be served upon them when deemed necessary, by the sheriff of the parish where they reside or where they may be found, the same as in cases of service of a notice to a witness in a civil proceeding.
La. R.S. § 45:1184