The wikipedia articles does include them in it’s description:
Examples of benefit societies include trade unions, friendly societies, credit unions, self-help groups, landsmanshaftn, immigrant hometown societies, fraternal organizations such as the Freemasons and the Oddfellows, coworking communities, and many others.
Anyone know how to start a mutual-aid society?
Well, first you have to know how to start a society in the first place.
It’s a specific kind of nonprofit organization.
...Interesting.
Similar to the fraternal organizations, like the Freemasons or Oddfellows?
Not so much.
The wikipedia articles does include them in it’s description: