Electricity in U.S.A. households (and not only there)

[kf4rca]

You CAN add breakers to a panel that appears to be filled up using a tandem breaker. Its basically two breakers built into the space of a single breaker.
I've seen them in the field but personally I would not use one.
I understand there are homes in Appalachia like the island home in my previous post. But they didn't have a front door view of the Atlantic.
After that summer job with SCE&G, I realized I wanted an air conditioned job like a TV station control room. The summers are HOT in SC!!!