There used to be regional Make & Take Prop Building groups. Lots of them were hosted in haunter homes or local places that allowed working on stuff (access to electrical/shelter/storage types of places). Folks would come work on a project decided on beforehand, hang out and get to know each other I believe on a monthly basis.
I also think the official haunter conventions used to attract lots of home haunters so they could check out the cool props, attend classes and such and hang out with other home/semipro haunters.
I imagine until the COVID nightmare dies down the actual getting together needs to wait, but it would be fun to see these come back around eventually. Some regions were more active than others, but I think we're hitting a wave of the OG haunters hanging up their shrouds and retiring over the last couple of years.