There's a loose organization of various Michigan GB groups called the Great Lakes Ghostbusters Coalition, a.k.a. GLGC.
https://www.facebook.com/GLGCMichigan Essentially, it's an effort to coordinate and invite other GBs to help bolster event attendance. If you're interested in attending evetns (comic cons, parades, etc.), check out the GLGC page. We have a private Facebook page too to discuss upcoming events and who can attend and such. Send a message to the public group if you're interested. We have a few different folks monitoring the public page and incoming messages.
Many of us have the Matty wands and have them modified to feed into an amplifier. There's a kit that's sold on GBfans.com that supposed to connect to the Matty wand as well, but I haven't used it. What we did is open the Matty wand (a bit of a challenge there) and splice into the speaker wires and feed that to the amplifier. Biggest challenge was drilling a hole on the inside of the Matty and then feeding the wire through the wand handle. Realistically, it probably took me an hour to two hours to drill and wire it up. Not knowing what to encounter, I took my time. Amplifier was something cheap from Amazon. It works well enough.
We've had some initial discussion of having a "build party" to create some of the new/reboot packs. Regardless if your for or against the reboot movie, it's part of the GB lore and and multi-dimentional universe. I know my kids loved it, so GB classic and new (and all the cartoons) are part of our household. We have some folks who want the classic packs too. Like it's been said, a "build party" is more of a motivator to start or finish a project. We had one a couple of months ago to make cardboard traps. It went very well! I've taken my cardboard trap to all the parades, comic cons and various events and it's held up surprisingly well. However, someday I'd like to make one that a bit more durable, but from a prop perspective, it looks good and does the job.
-Tom from Kalamazoo Ghostbusters
https://www.facebook.com/gbk.kalamazoo