Having the same problem, replaced the socket unit with a new one, still remains switched on regardless, yet , plug in an appliance, a drill, or whatever, no power comes from the socket.
I changed the socket unit, because the original. which was fitted some years ago by a so called "qualified " guy, had been doing the same, but I only discovered this, when I wanted
To switch it off?? I'm a bit baffled. anyone with any ideas, would be glad to hear from you,,,Stumped!!
Jack.., May 2016