A modular housing for mounting an electrical component on a grounding rail, the modular housing comprising: a plurality of housing slices (10, 122) and a pair of end covers (124, 126); each housing slice comprising opposite sides separated by a width, a first component support extending from one side to the other side, a second component support spaced from the first component support and extending from one side to the other side, and a floor between the first and second component supports, the floor extending from one side to the other side below the first and second component supports (38, 40); the housing slices (10, 122) being placed side-by-side, the housing slices (10, 122) being between the pair of end covers to form the modular housing, the first component supports being aligned with one another and cooperatively forming a first housing component support, the second component supports being aligned with one another and cooperatively forming a second housing component support, and the floors being aligned with one another and cooperatively forming a housing component floor being disposed below the first and second housing component supports; at least one of the housing slices carrying a grounding member, each at least one housing slice defining a cavity beneath the floor receiving the grounding member, the grounding member being a unitary member and comprising a grounding portion, a grounding terminal portion, and a lead portion connecting the grounding portion and the grounding terminal portion, the grounding portion being disposed to contact the grounding rail when the modular housing is mounted on the grounding rail, the lead portion extending from the cavity through the floor to the grounding terminal portion, the grounding terminal portion being disposed above the floor outside of the housing slice and not extending beyond the sides of the housing slice, characterized by each of the housing slices being configured to enable the housing slices to be placed side-by-side in any order between the end covers to define a first housing support and a second housing support capable of mounting the electrical component against the first and second mounting supports. a plurality of housing slices (10, 122) and a pair of end covers (124, 126); each housing slice comprising opposite sides separated by a width, a first component support extending from one side to the other side, a second component support spaced from the first component support and extending from one side to the other side, and a floor between the first and second component supports, the floor extending from one side to the other side below the first and second component supports (38, 40); the housing slices (10, 122) being placed side-by-side, the housing slices (10, 122) being between the pair of end covers to form the modular housing, the first component supports being aligned with one another and cooperatively forming a first housing component support, the second component supports being aligned with one another and cooperatively forming a second housing component support, and the floors being aligned with one another and cooperatively forming a housing component floor being disposed below the first and second housing component supports; at least one of the housing slices carrying a grounding member, each at least one housing slice defining a cavity beneath the floor receiving the grounding member, the grounding member being a unitary member and comprising a grounding portion, a grounding terminal portion, and a lead portion connecting the grounding portion and the grounding terminal portion, the grounding portion being disposed to contact the grounding rail when the modular housing is mounted on the grounding rail, the lead portion extending from the cavity through the floor to the grounding terminal portion, the grounding terminal portion being disposed above the floor outside of the housing slice and not extending beyond the sides of the housing slice, characterized by each of the housing slices being configured to enable the housing slices to be placed side-by-side in any order between the end covers to define a first housing support and a second housing support capable of mounting the electrical component against the first and second mounting supports.