For people that want the pack (but don't want the strangeness) someone has uploaded a save file with clean (fresh) premades and the mystery solved: http://modthesims.info/d/624696/not-so-strangervi...
It's strange (lol) but I have started a new game of my own in Strangerville (no mods) and the only strangeness I have seen in 2 sim weeks is one infected sim walking in the distance.