Abstract: A modular electric switch or wall socket comprises a pair of electrodes or screws inserted into a case to which are connected the terminals of electric current of the circuit it is desired to control, and a rockable block which actuates the breaking or connecting of the circuit. The case is a solid insulating box having a recess in its upper face and a slot inside the recess and forming steps with the bottom surface of the recess. On the steps are mounted two plates bent at right angles and placed opposite and facing each other in such a way that the vertical portions of these angular plates which are inserted into the inside of the slot bear firmly against and establish electrical contact with two posts inserted in the corresponding opposite sides of the walls of the case, to which posts the terminals of the electric circuit are connected.