When I was growing up, "WTF" meant "white trash female," usually said in connection with the trailer park across the tracks that one of my uncles evidently visited frequently for short intervals.
My Irish granny nearly had a stroke one day when my gramps left a note on the fridge saying, "WTF. Back in an hour." She was red-faced mad and cursing in Gaelic, almost clobbered him with an iron skillet when he returned, but then she noticed the bag of fresh veggies. He meant, "Went to Farm," as in the local farmer's market grocer.
Makes me grin NOW, although at the time my young mind was trying to figure out how and where to bury the body in the desert so granny wouldn't end up in jail.
(I still have that skillet. It's a family heirloom! My great, great grandmother on the Emerald Isle probably threatened her husband with it.)