A light access can be integrally formed with a light guide on at least one end of the light guide. A printed circuit board with an LED lamp mounted thereon can be press-fitted in the light access for transient arrangement, and can be fixed by a cover. The position of the printed circuit board can be determined in relation to the light guide. For example, engagement hooks of the light access can be fitted with recesses in the printed circuit board for positioning the circuit board in a plane normal to the longitudinal direction of the light guide. Similarly, positioning ribs of the light guide can be employed for positioning in the longitudinal direction of the light guide. The light guide can be formed in an almost rod shape having four sides in section normal to the longitudinal direction of the light guide. A light guide lens can be formed in one surface and a diffuser cut can be formed in the opposite surface of the light guide.