The ornamental design for a housing, substantially as shown and described.
FIG. 1 is a perspective view of my housing design;
FIG. 2 is a front view of my housing design;
FIG. 3 is a top view of my housing design;
FIG. 4 is a left-side view of my housing design;
FIG. 5 is a bottom view of my housing design;
FIG. 6 is a right-side view of my housing design; and,
FIG. 7 is a back view of my housing design.
The broken lines shown in the drawings are included for the purpose of illustrating unclaimed portions of the housing and form no part of the claimed design.