I'm pretty sore 100% of all US states mandate that all new construction adhere to the National Electrical Code (NEC). Specifically, NFPA 70. They just delegate the authority as to what's "standard" to that non-governmental body.

Every few years the National Fire Protection Agency (NFPA)--which is a non-governmental nonprofit--publishes an updated standard and then it's up to all the state legislatures to update the laws to require the new standard.

The problem is that the NFPA doesn't just post the NEC for free on the Internet. You have to pay for it (which is ridiculous) and it's copyrighted and as such, illegal to just give away. There was a lawsuit in Georgia that was supposed to determine whether or not that situation was OK (having laws that require expensive fees to view may be unconstitutional since that's like having secret laws). I don't know what the outcome was of that though.