I have never had my noncontact probe (a Fluke, FWIW) show a false negative, but false positive indications are pretty common, especially in proximity to other energized circuitry above 120V to ground.
I have converted a pair of dikes into a wirestripper by relying on (somebody else's) voltmeter, though. Open conductor inside the insulation of one of the test leads....
In addition to the pre-use check on a known energized circuit, a periodic check of the meter's leads using the continuity beeper is recommended.
