Im confused !

Hang on a minute, this is a bit of a paradox. When it was switched off, I agree that the sign wasn't in use but as soon as they added the letters "Sign not in use" then didn't the sign become In use again, telling us the vital information that it isn't in use. Hmmm, but if it isn't in use then how can it be telling me anything. OK, I'll start again, It isn't in use except for the information telling me that it isn't in use which is by definition a use, so it is and it isn't in use at the same time. This isn't helping is it !