The ornamental design for a housing for an actuator, as shown and described.
FIG. 1 is a perspective view of a housing for an actuator;
FIG. 2 is a front elevational view of the housing for the actuator of FIG. 1;
FIG. 3 is a rear elevational view of the housing for the actuator of FIG. 1;
FIG. 4 is a right side elevational view of the housing for the actuator of FIG. 1;
FIG. 5 is a left side elevational view of the housing for the actuator of FIG. 1;
FIG. 6 is top elevational view of the housing for the actuator of FIG. 1; and,
FIG. 7 is a bottom elevational view of the housing for the actuator of FIG. 1.
The broken lines shown in the figures are included for the purpose of illustrating portions of the housing for the actuator that form no part of the claimed design.