The ornamental design for a signlightdevice, as shown and described.
FIG. 1 is an upper top left front perspective view of the sign light device.
FIG. 2 is a lower bottom right front perspective view of the sign light device of FIG. 1.
FIG. 3 is a top view of the sign light device of FIG. 1.
FIG. 4 is a bottom view of the sign light device of FIG. 1.
FIG. 5 is a front view of the sign light device of FIG. 1
FIG. 6 is a rear view of the sign light device of FIG. 1.
FIG. 7 is a left side view of the sign light device of FIG. 1.
FIG. 8 is a right side view of the sign light device of FIG. 1; and,
FIG. 9 is a perspective view of the sign light device of FIG. 1 shown in position of use on a sign.
The broken lines in the figures representing fasteners, bulbs, LED's and a sign are for the purpose of illustrating environmental structure and form no part of the claimed design.