Why might hot and ground light a circuit tester; neutral and ground also light; but hot and neutral do not light a circuit tester?
I opened an old box to branch a new receptacle.
I used the circuit tester against the hot and neutral wires. It did not light.
I tested the circuit tester against hot and ground. It lit.
Neutral and ground also lit the tester.
I have never seen this before. What's going on? Is it possible the previous homeowner accidentally used ground for hot or neutral?