The component with the lowest price in the INTERIOR LIGHT-SWITCH schematic is the Bolt Earth (4x12z.
Parts such as the Interior Light-switch: Light Ass*nh220l*, Bolt Earth (4x12z, Lens, Light Trunk are included in the Civic Wagon 1989 (k) Wgn 4wd 1600 (ka,kl) Interior Light-switch parts fiche.