About stray or ghost voltages: because such a miniature neon light has a very high impedance, you also measure voltages generated by induction from nearby wiring. In the order of micro amperes. That's not a ‘hard voltage’: the moment you connect anything with a real load to it, that voltage disappears like snow in the springtime sun.
Measuring with a “Duspol” (low input impedance), for example, completely eliminates this type of measurement error. Because all modern digital multimeters also have a very high input impedance, they pose the same risk. A high input impedance of 10 MΩ means the circuit places minimal load on the signal source, nice for electronics, do not disturb what's going on inside, the principle of non-interference. Some manufacturers therefore also produce special meters for electricians that have a low-impedance range. Or they have a handy adapter that you can use as an attachment. And it's not rocket science inside such an adapter: only one resistor of about 3 K Ohm (1 to 2 Watts).
To chase ghosts you need ghost busters.
The Consuel attestation the next day: no problems.
