FIG. 1 is a perspective view of a dimmer switch according to a first embodiment of our new design.

FIG. 2 is a front view thereof.

FIG. 3 is a left side view thereof.

FIG. 4 is a right side view thereof.

FIG. 5 is a top view thereof.

FIG. 6 is a bottom view thereof.

FIG. 7 is a perspective view of a dimmer switch according to a second embodiment of our new design.

FIG. 8 is a front view thereof.

FIG. 9 is a left side view thereof.

FIG. 10 is a right side view thereof.

FIG. 11 is a top view thereof; and,

FIG. 12 is a bottom view thereof.

The rear views form no part of the design and are omitted. The portions of the drawings appearing in broken line are for environment only and do not form a part of the claimed design.