I changed some of the details but I know someone in the position I described and I don't have any good advice. I was hoping perhaps the denizens of HN might have interesting suggestions.

Sell your "problem solving skills". It's completely vague, but it's supposedly the essential skill you've learned (actually mathematical modeling, testing, and data analysis, hopefully).

Apply to any and all entry level engineering type jobs and just try to convince them that you are able to learn what they need as a physicist.

Better yet, go back to UW and get an MS in medical physics. They apparently only need a master's and make decent money.

You could try doing industrial research. Even without a PhD, talent is sought for industrial research labs. You may have to start as an assistant researcher or even lab technician, but you'll get promoted to researcher in no time if you're good.