To add an AC outlet, for example, you just drill a circular hole in the wall, tap into the wiring, add the outlet and you're set. If you don't want it, pull it out and plaster over it with more earth to seal the hole.
“The optimist proclaims that we live in the best of all possible worlds, and the pessimist fears this is true.”
“I was five years old when I wrote my first song. It was out of longing for my father that I wrote it.”