When Voice Actors Can't Break Character

What happens when an actor can't break character? And not for filming purposes or anything like that, but because they become so accustomed to being the character that they start to become the character.
And what if the character just happens to be a superhero?

This:

Life can be tough for voice actors.

This is my first exposure to the Daly Show with Tim and Sam (not to be confused with The Daily Show with John Stewart), and it's pretty great. I went ahead and watched the other episodes, and now I'm sad that I've wasted so much time not watching this web series.

From what I hear, I went through a pretty intense Superman phase when I was really young, and refused to wear anything other than my Superman Underoos. This is kind of like that, but with grown men.