The ornamental design for a controllerhousing for a lawn trimmer, as shown and described.
FIG. 1 is a front perspective view of a controller housing for a lawn trimmer in accordance with our new design;
FIG. 2 is a rear perspective view of the controller housing for a lawn trimmer in accordance with our new design;
FIG. 3 is a front elevational view of the controller housing for a lawn trimmer in accordance with our new design;
FIG. 4 is a rear elevational view of the controller housing for a lawn trimmer in accordance with our new design;
FIG. 5 is a top plan view of the controller housing for a lawn trimmer in accordance with our new design;
FIG. 6 is a bottom plan view of the controller housing for a lawn trimmer in accordance with our new design;
FIG. 7 is a right side elevational view of the controller housing for a lawn trimmer in accordance with our new design;
FIG. 8 is a left side elevational view of the controller housing for a lawn trimmer in accordance with our new design; and,
FIG. 9 is a front perspective view of the controller housing for a lawn trimmer in accordance with our new design illustrating a state in which the controller housing is attached to other parts of the lawn trimmer.
The broken line showing of environment in FIGS. 1, 2, and 4-9 forms no part of the claimed design.