Abstract: The invention relates to a workpiece, in particular a housing (6) for an electrical switch, and to a process for its production. The workpiece is composed of at least two workpiece parts (7, 8) of plastic, preferably a thermo-plastic, welded together by laser beams (11) along a joining zone (10), the two workpiece parts (7, 8) having a transmission coefficient and an absorption coefficient for the spectrum of the laser beams (11) which are different from one another, at least in subregions. The one, first workpiece part (8) is made to be at least partially transmitting for the laser beams (11) in the region from a first coupling-in zone (12), in which the laser beams (11) impinge on the first workpiece part (8), up to the joining zone (10), whereby part of the laser beams (11) can penetrate through the first workpiece part (8) and can penetrate into the second workpiece part (7) at a second coupling-in zone (13).