[RyanN]

Also to add, the house was built about 20 years ago, so this house was supposed to be built to the codes 20 years ago... Personally, I think it is safe to run a whole house on one wire and one 20 AMP circuit breaker as long as you assume the breaker will trip at 20 AMPs. The only reason to have more than one breaker is so you can run more stuff off of electricity. We've never had a breaker trip except once in my room when I plugged something in that shorted out. Hopefully this makes sense. I don't say it is right to run a house off of one breaker, I'm just saying that it is safe in regard that it won't make a fire as long as the circuit breaker works.