Yes, Ron Jeremy, the guy from all those, ahem, adult, movies was an Extra in Ghostbusters.

It’s true, confirmed by the man himself.

Source: ProtonCharging.com which seems to be some type of hardcore Ghostbusters fan site. I got there from a site called ToplessRobot.com, which is a mildly entertaining NSFW pop culture site. Don’t ask me how I got there.