Thank you very much! Wires are now in nuts, electrical taped, etc. A
handyman seems to be just the ticket and will be coming out soon. With
it taped up and the switch off, I feel comfortable turning the breaker
back on and restoring lights in my house.

I hadn't thought about options that didn't involve pulling up the
concrete base. Thanks for these tips, as well as the question mark
over setting the post in concrete.