FIG. 1 is a perspective view showing a first embodiment of my new ornamental design for a headlight for a carpet extractor; FIG. 2 is a front elevational view thereof; FIG. 3 is a top elevational view thereof; and, FIG. 4 is a right side elevational view thereof, the left side being a mirror image. The details shown in broken lines are shown for illustrative purposes only and form no part of the claimed design.