You Don't Have to Be a Star... you can play one on TV
Just what is a Seat Filler? According to Seat Fillers and More, "a seat filler's job is to fill all of the empty seats located in the camera section of the audience in an award show or televised special." What this means is that you get to sit in the first 10-15 rows of the theater when the camera pans the audience during the telecast so that there are no empty seats.
Why would there be empty seats? Celebrities have to go to the restroom (stars - they're just like us), get snacks, take breaks. And that's when the seat fillers get to work.
There are rules. There is a strict dress code. You are not guaranteed a seat. You are not allowed to interact with the actors or take pictures. But, you could find yourself sitting next to some of the biggest names in Hollywood when a TV camera points in your direction!
By the way, don't quit your day job. Most jobs are strictly volunteer!