France has nearly 20 million volunteers doing their bit, working with animals, teaching French (or English) to asylum-seekers, keeping nature parks or taming bureaucracy.
One in three volunteers is a retired over-65 year old and most want to ‘be useful in society”.
Paris mairie has a website of volunteering one-off ‘missions’ at jemengage.paris.fr which has a vast range of volunteer posts across the city.