Knoxville, Tennessee - Then and Now
Mockingbird Motel - 3 miles north on Highway 25W
Judging by the cars, I'd say this is late 60s.
It's hard to say exactly where the place was, but noticing the high tension power lines in the postcard allowed us to narrow it down to about here.
This looks like the floor of the building and the outline of the foundation.
And this looks like the pole just this side of the sign in the postcard.