Relevant to this topic: Keith Johnstone's 'Masks'. It would be better to read the relevant section in his book "Impro" for the whole story (I got it at my university library) but this collection of quotes followed by this video should give enough of an introduction.
The idea is that while the people wear these masks, they are able to become a character with a personality different from the actor's original. The actor doesn't feel as if they are controlling the character. That being said, it doesn't happen immediately: It can take a few sessions for the actor to get the feel for the thing. The other thing is that the Masks usually have to learn to talk (albeit at an advanced pace) eventually taking on the vocabulary of their host. It's very interesting reading, to say the least.
Thus spake Eliezer:
It seems that many here might have outlandish ideas for ways of improving our lives. For instance, a recent post advocated installing really bright lights as a way to boost alertness and productivity. We should not adopt such hacks into our dogma until we're pretty sure they work; however, one way of knowing whether a crazy idea works is to try implementing it, and you may have more ideas than you're planning to implement.
So: please post all such lifehack ideas! Even if you haven't tried them, even if they seem unlikely to work. Post them separately, unless some other way would be more appropriate. If you've tried some idea and it hasn't worked, it would be useful to post that too.