Electrical – How to test voltage between neutral and ground

From all this, I conclude the following is likely:

• Only the outlet in the kitchen next to the sink is properly wired.
• All other outlets have hot and neutral reversed.
• There is no ground connection.
• Unexpected observed voltages (mostly 60 volts) are caused by stray capacitance.

I'll mark it accepted when I get complete confirmation.

Outlets need to have their hot and neutral corrected. Outlets need to be grounded or labelled as "GFCI protected" and "no equipment ground."

Fluctuating voltage from the actually hot line to true ground (the water pipe) is caused by current flow reducing the electrical resistance of the line. Voltage is otherwise high and stable for the capacitive currents as they don't induce enough flow.

The best way to check for the bootleg ground, is to open up one of the boxes and look at how the receptacle is wired.

Since the grounded (neutral) and grounding conductors are bonded at the service equipment, they should always be at about the same voltage potential. If you had a long circuit, and an accurate meter, you might be able to measure a slight difference.

Since wire has a resistance, it's certainly possible to measure a voltage difference. However, a reading of 0 volts, does not necessarily mean there's a bootleg ground. The only way to know for sure, is to actually inspect the wiring.