I learned a while back how to get onto the set for a TV shoot: I just walked up to the security guard then said "I'm here to see Ted". In my case, I really was

I learned a while back how to get onto the set for a TV shoot: I just walked up to the security guard then said "I'm here to see Ted". In my case, I really was there to see my friend Ted Arabian, who was appearing in a TV commercial. But I expect that would work well in other cases. The key is to act as if you really belong there.