When I was a volunteer, I worked 4 hours a week (7pm to 11pm on Sundays). I sat at the triage desk and talked with the nurses there. When a space was free in the back, I'd escort the patient back to the appropriate cubicle. If the pt had family or friends with them, I'd give a visitor pass to that person. If a room needed cleaning, I'd strip the linens, wipe down all the flat surfaces with disinfectant wipes, and put new linens on. It's not glamorous, but the staff can tell who's in it for real experience, and who's marking time half-assedly so they can put something on an application later.
Me, I got to know the people and the place, and when I was certified EMT I got hired in that same Level 1 Trauma ED. So I got that goin' for me. Which is good.