The neutral safety switch on a 2007 Jeep Grand Cherokee is located on the
transmission. More specifically, it's part of the transmission's electrical components and is usually mounted
on the side of the transmission case itself, near where the shift linkage connects. It's not easily accessible without some mechanical knowledge and tools.
Because there's variation depending on the specific transmission (automatic vs. manual, and even different model numbers of automatics), you'll likely need to consult a repair manual specific to your Jeep's transmission type to pinpoint its exact location. A diagram in the repair manual would be incredibly helpful.