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.
“I don't fight the suburban areas or collar counties. I get along with them; they're former Chicagoans anyway.”
“Yet with great toil all that I can attain by long experience, and in learned schools, is for to know my knowledge is but vain, and those that think them wise, are greatest fools.”