garygid wrote:The L1 EVSE requires a Ground, or it will refuse to work.
Get your sockets properly Grounded.
If the only grounded socket that is available (even with a heavy-duty extension cord) is the GFI socket, consider having that socket replaced with a properly-grounded non-GFI socket.
FWIW, I turned off the outlet' breaker and opened it up: it is grounded. Or rather, there is a bare copper wire screwed into the outlet's ground screw; I did not verify where the other end of the wire goes, or checked for continuity between it and, say, the outlet's box.
I think I will get an outlet tester per DarkStar and test the outlet's sockets to see what's up, just out of curiosity.