Earthing a metal-plate phone socket

[plugwash]

man came to install sky a few years ago, youngish fella. came to installing the phone extension, all indoors, he fitted the plug-in piggy-back start of the lead and to test it he stuck the other end of the lead in his mouth! Cant be that much voltage there, just enough to tingle.

I see a Darwin Award in the making!

Did you know that a small but non-zero number of people die each year from testing PP3 (9V) batteries on their tongue?

Phone circuit is high (enough) impediance, unlike a PP3. Might have been interesting if someone rang while he had it in his mouth (but you did go on to say he didn't connect the ringer).

ring voltage goes on the main pair too its just we brits decided to put the ring cap in the master socket rather than in the phone itself.