Well, first of all, you have to be invited. In order for that to happen, you have to display good judgement and patience. Don't let things get to you or go to your head. Think about what you say before you say it. Like others say, Its a thankless job.
In my experience with the job on another site, I consider it a combination of Cop, IT manager, Janitor, and Babysitter.
Also, never ask for the job unless an admin wants you to.
Hope this helps.
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Who knows what evil lurks in the hearts of men?