Abstract: An electrical service switching device includes a contact point, a moveable contact piece, an auxiliary switch associated with the contact point and having a coupling element and an auxiliary switch contact point coupled to the moveable contact piece, the coupling element actuating the auxiliary switch contact point, and a T-shaped housing. The housing has a transverse web with two trailing narrow-side walls and a fastening surface perpendicular to the two trailing narrow-side walls, a longitudinal web with a leading front surface parallel to the fastening surface, leading narrow-side walls on both sides of the leading front surface, the leading narrow-side walls perpendicular to the leading front surface, and two trailing front surfaces parallel to the fastening surface. At least one of the two trailing front surfaces connects the transverse web and the longitudinal web. The auxiliary switch is releasably attachable to the housing.