This was asked by a friend of mine, and he wanted to know the answer. Upon searching for his polling location, he was given a special polling precinct and a general polling precinct, which were two different buildings. Is there a special occasion when he should go to the special precinct; why would he be given two precincts?
A special polling place is set up for those who have some sort of barrier to voting, such as your ID showing a different address than the one you live at, or refusing to sign/give an oath (under threat of perjury) that you really are who you say you are, and live where you say you live. These are set up by county, and as such, people who go to a special polling place can only vote for county level and up people, not local/municipality ones.