Jenn from westofthefifthmeridian.blogspot.ca posted this previously and I ran across this totally by coincidence a few days later on October 22, 2017. I was going to ask for the location and ended up stumbling across it before I could ask.
This is just off of Highway 590 west of Big Valley, Alberta south on Range Road 215. Someone has a great sense of humour.
Sure enough, just down the road is the invisible house. There is a ladder in the background being supported by nothing.
Right beside the invisible house on a fencepost is this sign. No see a lot of "No Hunting" and "No Trespassing" signs. This one is special.