The ornamental design for a switchplate, as shown and described.
FIG. 1 is a perspective view of a switch plate according to the present invention.
FIG. 2 is a front view of the switch plate of FIG. 1.
FIG. 3 is a top view of the switch plate of FIG. 1. The opposite bottom view is identical thereto; and,
FIG. 4 is a side view of the switch plate of FIG. 1. The opposite side view is identical thereto.
The rear of the switch plate of FIG. 1 forms no part of the claimed design. The dashed lines shown in the drawings illustrate portions of the switch plate that are not claimed and thus form no part of the claimed design.