I was too young unfortunately to remember hearing or seeing anything about Ghostbusters having a fan club in 1984. In 1985 my parents bought me a copy of The Official Ghostbusters Training Manual. Where it may have been advertised. I wouldn’t have remembered even the manual in detail until adulthood. Because they were closer in age I knew all about The Real Ghostbusters comics from NOW c o m i c s and The Real Ghostbusters Magazine(s).
As Ghostbusters grew older with me in an age before the internet an official fan club wasn’t in my Ghostbusters memory files. Unless it was just in the Official Training Manual I saw the fan club advertised in the role playing game books from West End Games in my 20s. I remember when I came across an ad and saw Ghostbusters magazine I was thinking why hasn’t any ghosthead seen these on-line?