---MIKE--- wrote:

Hobbyist asked:

When I switch my kettle off at the
electric socket, a brief flash of green
light is visible behind the socket. Is this
normal, or could it be dangerous?

It sounds like there is a loose connection to the socket. I suggest you
have it checked before you have a fire.

Thanks for your advice, Mike. Had a minor fire a few years back,
caused by lightning, so I don't want another. I'm definitely calling
that electrician.