Well, if I go to Toolstation and buy "an immersion switch with neon" (not that they are solely immersion switches) then that is what I will have - "an immersion switch with neon".
However I then wire the switch, or describe my wiring to anyone else, it will always be "an immersion switch with neon".
However I then wire the switch, or describe my wiring to anyone else, it will always be "an immersion switch with neon".