The dangers of these objects that are designed to prevent danger
The very object that is supposed to increase electrical safety can actually increase the chances of electric shock, why?
All UK sockets are designed to have shutters on them, covering the live contacts (live and neutral), these shutters are opened by the earth pin when a plug is inserted. The cover is effectively an insulated plug which is fine, and when inserted it does prevent little fingers and objects having access to the socket openings, it is when it’s removed that the danger presents itself!
Kids love to insert shapes into openings, maybe I’m showing my age but shape sorters etc were/maybe still are a popular toy, now imagine a child managing to remove the socket cover, turn it upside down and push the earth pin in, what does it do, opens the shutters on the socket exposing the live terminals, now they can get their little fingers into the live parts and that’s not likely to have an happy result.
We suggest disposing of these and let the sockets safe design provide the level of safety it’s intended to.