An assembly comprising electrical equipment and an electrical box: in which said electrical equipment comprises an equipment module to be engaged in the electrical box, said equipment module comprising: a base produced from an insulating material which delimits an interior space for receiving an electrical mechanism, means for retaining the base in the electrical box, and in which said electrical box comprises: a side wall which is closed at the rear by a bottom wall in order to delimit a housing for receiving said electrical equipment, complementary retaining means which cooperate with the retaining means of said electrical equipment, and characterized in that said equipment module comprises means for adjustment and for angular locking of the base with respect to the electrical box, which comprise at least one notch which is located on a tab of the base and which is movable in order to take up a deployed position towards the outside of the base, and which make it possible to lock the base in the electrical box between two extreme angular positions, and said electrical box comprises at least one window and complementary adjustment and angular locking means which comprise a catching surface to which the notch of the adjustment and angular locking means of said electrical equipment is adapted to be caught, said notch having a length which is strictly greater than the overall width of the notch or notches located on the tab; the electrical equipment comprises an element (10; 120) which is distinct from the equipment module, comprising an abutment (20; 122) which is adapted to automatically push said tab back towards its deployed position to assist with mounting of this element (10; 120) on the base of the equipment module. in which said electrical equipment comprises an equipment module to be engaged in the electrical box, said equipment module comprising: a base produced from an insulating material which delimits an interior space for receiving an electrical mechanism, means for retaining the base in the electrical box, and a base produced from an insulating material which delimits an interior space for receiving an electrical mechanism, means for retaining the base in the electrical box, and in which said electrical box comprises: a side wall which is closed at the rear by a bottom wall in order to delimit a housing for receiving said electrical equipment, complementary retaining means which cooperate with the retaining means of said electrical equipment, and a side wall which is closed at the rear by a bottom wall in order to delimit a housing for receiving said electrical equipment, complementary retaining means which cooperate with the retaining means of said electrical equipment, and characterized in that said equipment module comprises means for adjustment and for angular locking of the base with respect to the electrical box, which comprise at least one notch which is located on a tab of the base and which is movable in order to take up a deployed position towards the outside of the base, and which make it possible to lock the base in the electrical box between two extreme angular positions, and said electrical box comprises at least one window and complementary adjustment and angular locking means which comprise a catching surface to which the notch of the adjustment and angular locking means of said electrical equipment is adapted to be caught, said notch having a length which is strictly greater than the overall width of the notch or notches located on the tab; the electrical equipment comprises an element (10; 120) which is distinct from the equipment module, comprising an abutment (20; 122) which is adapted to automatically push said tab back towards its deployed position to assist with mounting of this element (10; 120) on the base of the equipment module.