What is it about a certain candidate in the SC House District 17 special election that runs for office with varying addresses?

Can you run for office out of a PO BOX? Apparently in Greenville County you can.

In the race for House District 17 in North Greenville County, five people are running for office. All of them have street addresses except one, Christopher Sullivan. This is the same Christopher Sullivan that ran for Senate District 6 against incumbent Mike Fair in the 2012 GOP primary and lost.