Oddly enough Ragnar,
There is a whole Code of Practice here in New Zealand for the Sale of Second-hand Electrical Appliances.
The name of which escapes me (ECP 53??).
If I ever go to a junk sale here, I take test gear with me. [Linked Image]
I even tested out a range for a guy locally here at a clearing sale, it gave the lowest Insulation Resistance test I've ever seen.
I might be on the Black-list of Garage Sale vendors.
I think they've all been warned, "Just look out if anyone brings that idiot Trump here, if he turns up, close down your Garage sale and Run!!!.
Don't let him ask you any questions, it just helps him".
[Linked Image]