For your amusement:
High impedance meters/ digital auto-ranging meters us solid state chips to dope out the values.
In particular they us RC circuits: Resistance + Capacitance. The resistance is considered the known as is the capacitance. An extremely high frequency switching circuit clocks/times the circuit.
Upon test lead contact, current fills up an entire array of femto-capacitors. Then using the wizardry of digital logic resistance or voltage is back calculated in the blink of an eye.
Because the chip's capacitors are s-o-o-o tiny even the tiniest amount of current can fill them up. This is where false positives come from -- especially from either static electricity or by induction or capacitive effects.
In comparison, a Simpson analog meter is driven by a sequence of entirely separate 'ranged' circuits selected by dialing a stepping switch/knob. Thus it can't be 'autoranging.'
However, in an analog meter the current or voltage is shunted through resistors, coils and whatnot so as to provide a nearly linear response to the current or voltage which can then be read out on a swinging beam across a field of values. Such 'analog circuits' can't be faked out because they are driven by the laws of electricity -- directly. ( No brain assumptions )
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It is highly desirable to have both types + an influence / non-contact tester if you want to make rapid steady progress at all times.
For super speed, the voltage-tick/ non-contact tester can work wonders, especially on circuits you, yourself installed.
When facing the unknown -- face it -- you just can't trust anything. This is especially true with Churches and any 'owner-installed' projects. With them wire color means nothing. Black could be on any phase and at any voltage and even be neutral or ground. As time goes by you'll be astounded as to how crazy some buildings are wired. That's why:
Always start with voltage-tick,
Then DDM, with auto ranging,
If you're suspicious of false positives fall back to an analog meter.
Analog meters out of China go for a whopping $13 at Harbor Freight. That makes them cheaper than a voltage tick! ( And just about the same weight.)
For DMM I prefer Fluke or Greenlee. If they ever go dead check both batteries AND fuses -- inside.
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Slightly off topic: DeWalt battery chargers have a hard-wired fuse in them. The VAST bulk of dead chargers have simply blown this fuse! Open yours up, you can't miss it. It's easy to test for 'open.'
