I have decided to add another plug outlet near an existing blind outlet box. Unfortunately I've found that the existing one doesn't have ground since it's an old building, but that's a problem for another day.
After connecting the new outlet, the wiring was as follows:
socket L---L wire L---L house wiring socket G---G wire G no wire socket N---N wire N---N house wiring
However, using a tester screwdriver, the ground appeared live. Assuming that it's likely the socket that's the issue, I disconnected the socket ground, however the wire still appeared to be live. There was no load connected to that particular socket when testing.
Additionally, disconnecting the wire and using an auto-ranging multimeter between ground and live did not show any connection.
Is it just inductance screwing with me? A bad wire (it's solid core if that changes anything)?
I'm well aware that ground should be there and connected, but at this point I'm just moving an existing device to the other side of the room and it will remain on the same circuit as it's been for years.