(a) A subpena may be served by a United States marshal or his deputy, by Commission personnel, or by any person who is not a party to the proceeding and is not less than 18 years of age.

(b) Service of a subpena upon the person named therein shall be made by exhibiting the original subpena to him, by reading the original subpena to him if he is unable to read, by delivering the duplicate subpena to him, and by tendering to him the fees for one day's attendance at the proceeding to which he is summoned and the mileage allowed by law. If the subpena is issued on behalf of the United States or an officer or agency thereof, attendance fees and mileage need not be tendered.