Oh, you mean "chartered" non-profits. Sounds like you're not interested in teaching or government work. Greenpeace or some other activist group? Don't know whether UL is actually chartered as non-profit, but might be someplace to send a resume. Consumer advocacy groups, can't think of any specific ones, and ladder problems tend to get tiresome. "Think tanks" are reserved more for people who've made names elsewhere rather than as starting positions. And you might try looking at some of the "childrens' hospitals" in terms of "imaging" support staff.