Genuine Irony is cheap these days. Fresh Ideas are not.

Sign on Muni: Information Gladly Given but Safety Requires Avoiding Unnecessary Conversation

I need these folders

At the tire shop: things we found in tires

Seen when I was paddle boarding

Before you can eat it, it will clean your kitchen

Maybe the quotes should be around the word "dump"

This house does not have a back door

Seen in a bathroom near the running trail

As seen in New Orleans
See also signs from: More USA, Vietnam, Even More USA, Thailand, Chinese, South America.
What makes a sign funny to you? What's the funniest sign you have seen? Does bad grammar on signs make you cringe/laugh/whip out your camera?