Tough call! Whether or not to go through with it varies by person obviously, but here are my thoughts.
Don't work:
I'm also FIREd, for 18 months now. One of the nicest things about being fired is the pro/con balance. Maybe 100% literally, the ONLY con is I don't get paid money anymore -- which isn't all that huge of a con because I don't "need" money and I'm not even fully convinced more money would make me happier.
Work
Contrast that with working again, even part time. There are definite pros, but there are also very real cons, even if you like the job. "Having" to wake up, report to work, appease a boss, appease clients. Even if you try to half-ass it, everyone has at least some part of their brain that feels pressure to perform well, do a good job, push yourself, etc.
My verdict: I think it comes down to, can you take this job with 1. a minimum of stress and 2. an easy opt-out strategy if you find you don't like it. Doing something, finding it sucks and isn't what you hoped, and quitting is often actually a good thing in disguise, because at least you learned and you got to experience something. new. Would this be like that? Or would this be something you'd potentially actually regret?
There's no way to know of course. But at least for me, it comes mostly down to, does the benefit of trying something new and getting paid to do it, outweigh the cons of it potentially being not fun and a return to the prior crummy days of working.
Sorry, to be honest, that all just seems like a long way of saying "who knows."