The ornamental design for a switchhousingplatform, as shown and described.
FIG. 1 is a top plan view of the switch housing platform showing my new design;
FIG. 2 is a top perspective view thereof;
FIG. 3 is a bottom plan view thereof; and,
FIG. 4 is a bottom perspective view thereof.
The broken line disclosures shown in the Figures of the switch housing platform are for illustrative purposes only and form no part of the claimed design.