Слушьте, а может прям при музее они и есть? Вoт посмотрела есть для начала волнтерские программы в Метрополитен :  Guided Tour Programs for Adults 2016–17Weekend Guided Highlights ToursVolunteers in this program conduct regularly scheduled Highlights Tours designed to give visitors a general introduction to the Museum's collection. These tours are given in English and on weekdays in nine other languages (see International Guided Tours below).Weekday International Guided Tours"International Guided Tours are designed to introduce international visitors to the Museum's collection. These tours are offered in nine languages: French, German, Italian, Japanese, Korean, Mandarin, Portuguese, Russian, and Spanish. Candidates for this program must be proficient in English in addition to the language in which they will be conducting tours. All training is conducted in English."