A switching device for an encapsulated electric power distribution switchgear and an electric power distribution switchgear with at least one such switching device are disclosed. The switching device has a first electrically conducting housing which encloses an actuator mechanism for a first contact assembly and a second electrically conducting housing which encloses a second contact assembly. The first electrically conducting housing is arranged at a distance from the second electrically conducting housing. The switching device further has a third housing which is electrically insulating and arranged between the first electrically conducting housing and the second electrically conducting housing. The switching device is a puffer type switch.