(1) All employees whose names appear on the list certified by the division as being a complete list of the employees within the defined appropriate

unit shall be eligible to vote.

(2) Any prospective voter may be challenged for cause.

(3) All employees whose names do not appear upon the list certified by the division as being a complete list of the employees within the defined appropriate unit shall be challenged by the agent of the division.

(4) A challenged voter shall be permitted to vote but his ballot shall not be cast. It shall instead be sealed in a separate, unmarked envelope under the supervision of the employee of the division and then inserted in a special identifiable form envelope provided by the division for that purpose and returned to the division.