Section 501 - Election; vacancies(a) Three county commissioners shall be elected in each county in the year one thousand nine hundred and fifty-five, and every fourth year thereafter. In the election of commissioners, each qualified elector shall vote for no more than two persons. The three persons having the highest number of votes shall be elected.(b) Any casual vacancy in the office of county commissioners shall be filed, for the balance of the unexpired term, by the court of common pleas of the county in which such vacancy shall occur by the appointment of a registered elector of the county who was a member of the same political party as the commissioner whose place is to be filled at the time the commissioner was elected.1955, Aug. 9, P.L. 323, § 501.