The Health and Safety officer for our company often unintentionally gives everyone a good laugh. She put a note behind the kitchen taps (faucets) that said 'Warning: Water Hot'. Someone wrote underneath 'Elephants are big'! On another occasion she circulated a notice about the dangers of sharp knives. She removed all sharp kitchen knives from the drawers leaving only the only the everyday cutlery. As these knives weren't good enough even to cut up fruit cake there was a high demand for the use of the knife I happen to keep in my desk drawer. The sharp knives miraculously reappeared after a few of weeks!
Giving directions to outsiders using your washroom is hard, and so one of the picture frames in our wash room, decently displayed the following message:
"We aim to please...you aim too, please"
Talking of kitchen tales, there is one which goes like :
"I've been on a diet for seven days. So far I have only lost a week."
...but I still haven't found what I'm looking for.