"Night Auditor" is the glorified term for a hotel front desk clerk that works the graveyard shift (typically 11 P.M. to 7 A.M). This is a nice job if you don't like dealing with people, but those few that you do have to deal with tend to be mentally ill and/or intoxicated. An upside to this job is that you're likely to be hired or keep this job despite your incompetence or criminal record, as no one else is willing to work this shift.
The usual tasks involved in this job include checking guests in and out of the hotel, running end-of-day reports for the management, making coffee for the early birds, and playing lots and lots of solitaire. Common symptoms of being a night auditor include the inability to see in the sunlight and considering more than one car sharing the road with you to be "traffic."