Read the Sign. Please!!!

I have absolutely no theories about this unique sign. I don't want to imagine the circumstances that went into the need for its posting. I think this is one of the imponderables of modern society and should be left for quiet contemplation. Leave well enough alone, is what I always say. Just don't go there. Oh, the sign is hard to read so you will have to click on the photo to enlarge it. If you recognize this sign you will realize my wife took this photograph.