Where Does the Money Go?

What are the restrictions on the use of campaign contributions once you bow out of a race? I am assuming it is theirs to keep for campaign purposes. But what if they want to get out of politics all together? Where does the money go then?

It seems like a nice racket to get into: Announce your run, get a bunch of contributions, back out a few months later, and pocket the cash. Barbour, Santorum, Guiliani and Trump come to mind as people playing this “I will never win but it is a good way to get money” kind of game.

So what are the rules on the use of campaign contributions after you leave the race?

IIRC, you can transfer it to other campaigns. So presumably a retiring politicians gives it to whoever is running for their party to replace them.

For obvious reasons you can’t just pocket it, though some people do sketchy things like make their spouses and children campaign advisors and pay them a couple hundred thousand dollar salaries out of the campaign fund.