Well, when I moved into my new place my friend spotted my fan; the front of it, the protective grid, that is, fell off years ago and stuff. So he looks at me, points at it, and says, "Why has you maltracted your wife?"
He realised what he said afterwards when I gave him my biggest "WTF"-face. It was particularly humorous for us because English isn't our mother-tongue (but we're damned good at it, save these mishaps).
The same friend also managed to exchange the word "vegetarian" with "African" when we were discussing what food we could make.
I also have three separate books on the subject - allow me to quote a bit. Keep in mind some of these are more poor English than actual misuse, but...
"You are hardly welcome. The lift is broken so you must use our traps." - Hotel owner in South Norway when welcoming a few foreign guests.
"Due to customs regulations, there will be no service between these two legs." - Air hostess between London-Stavanger-Bergen.
"The unorganized conference... Er, I'm sorry, the UN organized conference..." - BBC Radio.
"Can we take photos here?" "Yes, but no flashing in the Cathedral, please." - Norwegian tourist guide in the Nidaros Cathedral in Trondheim.
But yeah, three books filled with stuff like this - so I've had my fair share of laughs.