In his second term on the Manhattan Beach City Council, Mitch Ward is familiar with the local political stage. Yet since moving to California, he’s strayed from his New York City acting roots in theater. Ward returns under the glaring lights of the Hollywood stage beginning this weekend and co-stars in the Cambridge Players - Next Generation production of the comedy/mystery “Reunion in Bartersville,” a play about a 50th high school reunion that takes a mysterious turn. “Reuni