A key switch mechanism (400, 500, 700, 880) comprising: a key button; a plunger attached to the key button and displaceable between a neutral position and an activation position; an elastomeric dome which, when the plunger is in the neutral position, is non-deformed and which, when the plunger is in the activation position, is elastically deformed by the plunger; a conductive spring having a stationary end portion and a moveable end portion, the stationary end portion electrically coupled to a circuit, and the moveable end portion coupled to the elastomeric dome in a manner to be moved when the plunger is displaced towards the activation position, in connection with the corresponding deformation of the elastomeric dome; and an electrical contact electrically coupled to the circuit, wherein, when the plunger is in the neutral position, the electrical contact is arranged at a distance from the moveable end portion, and, when the plunger is in the activation position, the moveable end portion is moved to contact the electrical contact; characterized in that the key switch mechanism (400, 500, 700, 880) further comprises: a light emitter arranged under the elastomeric dome; wherein the elastomeric dome, the plunger and the key button are each at least partially light permeable; and wherein the moveable end portion comprises a through hole, the through hole at least partially fitting over and around the elastomeric dome to couple the moveable end portion to the elastomeric dome. a key button; a plunger attached to the key button and displaceable between a neutral position and an activation position; an elastomeric dome which, when the plunger is in the neutral position, is non-deformed and which, when the plunger is in the activation position, is elastically deformed by the plunger; a conductive spring having a stationary end portion and a moveable end portion, the stationary end portion electrically coupled to a circuit, and the moveable end portion coupled to the elastomeric dome in a manner to be moved when the plunger is displaced towards the activation position, in connection with the corresponding deformation of the elastomeric dome; and an electrical contact electrically coupled to the circuit, wherein, when the plunger is in the neutral position, the electrical contact is arranged at a distance from the moveable end portion, and, when the plunger is in the activation position, the moveable end portion is moved to contact the electrical contact; characterized in that the key switch mechanism (400, 500, 700, 880) further comprises: a light emitter arranged under the elastomeric dome; wherein the elastomeric dome, the plunger and the key button are each at least partially light permeable; and wherein the moveable end portion comprises a through hole, the through hole at least partially fitting over and around the elastomeric dome to couple the moveable end portion to the elastomeric dome. a light emitter arranged under the elastomeric dome; wherein the elastomeric dome, the plunger and the key button are each at least partially light permeable; and wherein the moveable end portion comprises a through hole, the through hole at least partially fitting over and around the elastomeric dome to couple the moveable end portion to the elastomeric dome.