Abstract: A device for attenuating electromagnetic disturbances given off by at least one electronic component, arranged on a printed circuit board mounted on a first face of a board support and bearing at least one light-emitting diode driven by the at least one electronic component for the emission of light rays. A containment cage is arranged around at least the electronic component, it is formed partially by walls made of a piece with the first face and on which the printed circuit board rests, so as to delimit a wave containment zone. The containment zone has an opening, in a first direction, suitable for being blocked or not by a closure piece distinct from the walls. The invention further relates to a light module equipped with such a device, and a motor vehicle comprising a light module according to the invention.