Paradoxical signs (or how to confuse a Q.?)

I am intrigued by signs like 'This door is alarmed' as I always wonder by what and how? Or 'This gate should remained locked at all times', if so why put a gate there if it cannot be used? Why do I mention these? Well...there are the words 'Be still and know that I am God' in a significant place in the Meeting House but I discovered a sign today, which I must paraphrase because I had no means of copying it, which said 'If you are still it will go dark but if you move the light will come on'. ( Not saying where I saw it but it must be in several similar places.)
It has intrigued me for the last few hours. Yes I know what it means but in a Meeting House... well it made me laugh anyway! I wish I had a friend called Jake, Jack or Jacques so that I know that someone would be privy to my mind and humour also.
Peter