The switch has at least one contact plate, mounted on the inner side of an insulating wall forming one side of a casing. The contact plate has a contact rail or some other contact element which is engageable by a contactor on a movable carriage within the casing. The contact plate has a mounting hole surrounded by a circular flange extruded from or otherwise formed in one piece with the contact plate. A terminal bar is mounted against the outer side of the insulating wall and is connected to the contact plate by a terminal rivet, extending through the circular flange with an interference fit to establish good electrical contact therewith. The rivet also extends through an opening in the insulating wall and a mounting hole in the terminal bar. The swaging of the rivet causes the shank of the rivet to bulge outwardly, thereby expanding the circular flange and establishing a heavy interference fit between the flange and the swaged rivet, to establish and maintain low-resistance electrical contact between the flange and the rivet. Initially, the flange is preferably tapered, but is expanded by the bulging of the swaged rivet. The bulging of the swaged rivet also preferably establishes an interference fit between the rivet and the mounting hole in the terminal bar, to assure low-resistance electrical contact between the rivet and the terminal bar.