These are supposedly actual signs that have appeared at various locations.
At a restaurant in New York: "Tip-ing is not a city in China."
Here is a great sign I saw in the grocery store: "Snickers, 5 for 1.00$.(limit 4)"
On a dock in Juneau, Alaska: "Safety ladder, climb at own risk."
Seen on an electrical appliance store in Spokane, WA "Go modern! Go gas! Go BOOM!"
Emergency Evacuation Plan posted in various places around my office building: "Run like Anything!"
Biggs Septic Tank Service (near Nashville Tennessee) "Call Monday thru Friday, sorry, we haul milk on weekends."
Sign on the wall of the office of an ethnologist: "Beware of bargains in 1. Parachutes 2. Life preservers 3. Brain surgery 4. Eye Care
Billboard sign on a highway coming out of Austin, TX: "Nobody reads billboards.... But you just did :)"