The ornamental design for an electricaltestinginstrument, as shown.
FIG. 1 is a front elevational view of the electrical testing instrument
showing my new design, the cord broken away indicating indeterminate
length;
FIG. 2 is a top plan view of the upper and lower elements of the instrument
of FIG. 1, the bottom plan being a substantially mirror image thereof; and
FIG. 3 is a left end elevational view of the upper element of the
instrument of FIG. 1, the _left end elevational view of the lower element
of the instrument of FIG. 1 omitted for ease of illustration, being
substantially similar to that shown.