Braille signs

One of the things I've always wondered about lately is: how do blind people find Braille signs?

Seriously? It's not like there is a rule that the signs will always be at a certain place in a room. So how do blind people even find them to begin with? It all seems like a really mean practical joke to me, and a bit of a waste of resources. Of course the reason why I'm pondering this question is the sign that I saw in a coffee shop restroom, below:

I wonder if the Braille actually says "Employees must wash hands". I would think that a better sentence would be:
"Bet you'll wash your hands now that you finally found this sign!"