Charles de Lint
One day, Max Trader, successful luthier, wakes up in someone else's body. As you can imagine, this is a bit of a shock. It turns out that this was a straight-across switch; the man who he switched with - Johnny Devlin - is in his body, but unlike Max, has no interest in trying to fix the situation. And to make matters worse, Devlin was in deep financial trouble; Max soon finds himself with no apartment, no job, and no money, as well as vestiges of Devlin's personality, such as severe mood swings.
This is another novel about just getting by. It is obvious why Devlin would like to have someone else's life, but Max is a bit harder. He's successful at doing what he loves, but as he begins to reflect on his situation he realizes that he was drifting nonetheless - which left him open for a random bit of magic to steal his life away.
And with the help of a stray dog, his young friend Nia, and Zeffy, a woman who has reason to hate Devlin (and who can't quite believe that Max is who he says he is), he's going to do what he can to get his life back.
Charles de Lint has presented a slightly hallucinatory story about the importance of being conscious, and of realizing the importance that one has on the world. It is obvious that Devlin has never outgrown the selfish perspective of a child who believes that the world revolves around him, but it becomes clear that maybe Max needs to grow up a bit as well. This is well worth a read, but it's not exactly easy on the senseless magic, so don't expect a book that is, except for the premise, entirely set in this world.