Times change and a remodel job allows all sorts of updating. I am in the process of renovating a kitchen which had a wired internet jack. Nowadays, home users use wireless internet connections as they are so much more convenient. The homeowner asked me if I could remove the old jack, which I’ll illustrate in the photos below.

Here I’m removing the cover plate. Apparently, they already got rid of the jacks.
The wires are still present, but they are no longer connected to anything so they can stay.
I cut out a small piece of drywall somewhat larger than the outlet hole.
I then cut out the excess drywall from the back leaving the paper intact.
It looks like a perfect fit!
Now some joint compound for both sides.
Everything smoothed out using a putty knife. Ready for its finishing.