Most of the time in the TV Universe, the actors who play the Toobworld characters also exist on Earth Prime-Time and as actors there as well.
Here's a good example - thanks to 'The Larry Sanders Show', Peter Falk is known to be an actor in the same dimension as Lt. Columbo, Daniel J. O'Brien, Max the Christmas Angel, and Ramos Clemente, the late, unlamented Latin American dictator - among many other roles given life by Falk.
But just because an actor plays characters on TV, that doesn't mean his TV twin is an actor as well. And the season premiere of 'Fringe' helps prove that point.
Neil Schell appeared on the Senate sub-committee as the one senator who wanted to support Special Agent Broyles (but found it difficult to do so, given the lack of results).
And the name of that senator? He was also Neil Schell.
Therefore, even though Neil Schell is an actor in our world, he's a United States senator in Toobworld!