Firstly, I'd like to thank everyone who writes here. I've been doing
my first (and last) renovation over the last three years and the
advice here has been invaluable even though I've hardly had to post
myself.

I wonder if anyone can work out what's going on he

I've just replaced plastic light switches with ones that have metal
faceplates, and I *just* can feel electricity when I brush my fingers
against them lightly. I'm certain it's not static -- I can feel the
50hz cycle.

It only happens on one lighting circuit; on other circuits with the
same new switches you can't feel anything.

Does this mean that the earth on that circuit isn't connected? Or
that it is connected and there's electricity flowing continuously to
earth due to a fault, a little of which diverts through me when I
touch the switches? Should I ignore it or try to fix? (The case of
my new laptop feels the same sometimes and the user's manual says it's
normal.)

Any advice appreciated as always.