WWE security DOESN'T PLAY AROUND -- they sprung into action to take down a ring invader they believed was a crazed fan ... only to learn he was SUPPOSED to be there!
Here's the deal ... as WWE superstar A.J. Styles was leaving the ring before a commercial break, a man dressed as a pastor ran inside the ring to get ready for an upcoming segment.
Security raced after the dude and took him down FAST -- confusing viewers at home who had no idea what was going on.
Here's the real story .