Socket Switch "Keep On" Cover

I have a socket with a plug in it that runs my entire aquarium setup & cannot be switched off. I already have a label but this does not prevent the switch from actually being turned off. So I designed and printed this. It can either be permanently attached using a few small drops of super glue or less permanently attached using Blu-Tack or thin strips of double-sided tape. It features a very small slot which will not fit even the smalles fingers but will allow it to be switched off if it ever ne