FIG. 1 is a perspective view of the electrostatic spray gun; FIG. 2 is a front elevation view thereof; FIG. 3 is a rear elevation view thereof; FIG. 4 is a left side elevation view thereof; FIG. 5 is a right side elevation view thereof; FIG. 6 is a top elevation view thereof; FIG. 7 is a bottom elevation view thereof. FIG. 8 is a perspective view of an alternate embodiment of the electrostatic spray gun; FIG. 9 is a front elevation view of the alternate embodiment; FIG. 10 is a rear elevation view of the alternate embodiment; FIG. 11 is a left side elevation view of the alternate embodiment; FIG. 12 is a right side elevation view of the alternate embodiment; FIG. 13 is a top elevation view of the alternate embodiment; and, FIG. 14 is a bottom elevation view of the alternate embodiment.