The event in question is the "Whateverworks" event. The tickets ARE free - get the Cameo staff to check at the desk if they seem uncertain. The start time is either 6:30 or 7:00 pm - this is still being confirmed, but I'll update you as soon as I know.
I have been told that tickets will only be available by phonecall on the day. I'm still confirming reserved tickets for cast and crew.
I'll update more as various other things get confirmed.