It does sound like a really interesting job! I'd take it in a hot second! And if the bills are piling up, you may need to take a job outside nursing. Having food to eat and a roof over your head trumps all other considerations.
I have to be honest, though. In my experience as an LVN, a job in a related field or as a volunteer is not considered experience to a nurse recruiter. It will perhaps make you more attractive a candidate than someone else, because it makes you more well-rounded and shows initiative.
If you choose to volunteer at a place that could theoretically hire you, you will have the opportunity to network, and could be a real plus providing you don't give people the impression that you are only volunteering to get a "shoe in" the door.
Having said all that, what we are experiencing in the field right now will cause us to throw out the rule book we've relied on for decades. Anyone who's job it is to hire nurses would have to live in a cave not to know that we are far from normal times, and more accepting of the idea of a job outside nursing is a necessity for many people.
You mentioned the agency job. Have you looked into private duty care through an agency? Ours hired a new grad, and though we are filling up quickly, there are opportunites out there. Best wishes to you.