On Mar 22, 5:16*pm, "John D99" wrote:
We bought this house about 7 years ago, and after a few years the carpeting
in the living room went from normally taught to having wrinkles - some of
these get to about an inch above the wood substrate.

What's the best way to correct this?

Carpet stretcher. You'll probably need to cut a little off one side
when you do this.