Switch module of an electrical installation switch, which is embodied as a rocker switch or a momentary-contact rocker switch, having a switching housing, having a switching rocker, which is mounted in a pivotable manner and impinges on at least one movable contact piece (51, 52), which makes contact with at least one stationary contact piece (61, 81) in a manner likewise mounted in a pivotable manner in the stable position thereof, by virtue of the switching rocker acting on a contact rocker, which is arranged in the switching housing, by means of a spring-mounted movable plunger or peg, • the contact rocker is designed with at least one movable contact piece (51, 52), • at least two switching contact connection or contact terminals (60, 70, 80) are provided in the switch module, which terminals are provided with at least one stationary contact piece (61, 81) and with a contact rocker bearing and can be electrically connected to the contact rocker, which can be impinged upon by the switching rocker, • the contact rocker bearing is formed as an L-shaped stamped-and-bent part part, which is referred to as a knife-edge bearing, composed of electrically conductive metal, against the first limb of which the contact rocker abuts and thus forms an abutment surface and an axis of rotation for the contact rocker, characterized • in that an end piece with a rectangular cross section is integrally formed on the first limb, • in that the knife-edge bearing abuts by way of its end piece directly against one of the switching contact connection or contact terminals and is electrically conductively connected thereto, and • in that the connection or contact terminal, against which the knife-edge bearing abuts or by which said knife-edge bearing is received, is arranged in a manner offset in parallel with one of the connection or contact terminals (60 80) that is fitted with the stationary contact piece (61, 81). • the contact rocker is designed with at least one movable contact piece (51, 52), • at least two switching contact connection or contact terminals (60, 70, 80) are provided in the switch module, which terminals are provided with at least one stationary contact piece (61, 81) and with a contact rocker bearing and can be electrically connected to the contact rocker, which can be impinged upon by the switching rocker, • the contact rocker bearing is formed as an L-shaped stamped-and-bent part part, which is referred to as a knife-edge bearing, composed of electrically conductive metal, against the first limb of which the contact rocker abuts and thus forms an abutment surface and an axis of rotation for the contact rocker, characterized • in that an end piece with a rectangular cross section is integrally formed on the first limb, • in that the knife-edge bearing abuts by way of its end piece directly against one of the switching contact connection or contact terminals and is electrically conductively connected thereto, and • in that the connection or contact terminal, against which the knife-edge bearing abuts or by which said knife-edge bearing is received, is arranged in a manner offset in parallel with one of the connection or contact terminals (60 80) that is fitted with the stationary contact piece (61, 81).