[anomie]

When my grandparents died and we sold their house (in the uk) we had some builders in to tidy up some stuff and they discovered that in a big part of the house the earth was actually wired to live in the sockets. They'd lived with it for 40 years or something. Guess not many devices actually use the earth.

(The wiring was originally done by my grandad'a brother - use a professional people...)

[taco_emoji]

If you're not going to do it professionally, at least use one of these:

http://smile.amazon.com/GE-3-Wire-Receptacle-Tester-50542/dp...

(that's US wiring but surely there's a UK equivalent)

[mturmon]

Nothing wrong with that device, but it's also nice to know about its big brother:

http://smile.amazon.com/Amprobe-INSP-3-Wiring-Inspection-Tes...

This tester can simulate a 10A or 15A load and measure voltage drop, which should remain within 5% of its unloaded value (this is the recommendation in U.S. code). This can identify situations where connections are weak, or wires are too long or too thin.

It has also helped me to improve my wiring practices. It turns out that keeping voltage within 5%, under a 15A load on a 20A circuit, is pretty demanding, and a series of (say) 8 or 10 twisted connections may not meet it, if you are not careful with your technique.

The device can also test GFCI outlets by allowing some current to leak to ground. This provides an end-to-end test in situations where the GFCI is not present at the outlet.

[riffraff]

I've found earth and live wires mixed in 2 different houses I've lived in. Programmers are not the only ones that do shoddy work :)