The ornamental design for a decorative treelightset, as shown and described.
FIG. 1 is a side elevational view of the decorative tree light set in a
display position. All side elevational views are identical to that shown
in FIG. 1. The Christmas tree shown in dashed lines is not part of the
invention but is shown to indicate the environment for the decorative tree
light set and to indicate how it is to be used;
FIG. 2 is a plan view of the invention laid out on a flat surface;
FIG 3 is a top plan view of the decorative tree light set of the present
invention in the display position. The Christmas tree shown in FIG. 1 is
not shown; and,
FIG. 4 is a bottom plan view of the decorative tree light set of the
present invention in the display position. The Christmas tree shown in
FIG. 1 is not shown.