I think Ford used that pin in the rear hubs till about 1984. At least our 1983 chassis used them and it didn't seem later years did. The wheels weren't hub-centered (aka hub-piloted) but rather they were "Coined". Every other lug hole was recessed or raised. Inner wheel's recess had to match outer wheel's raised and the pin lining up in a hole assured that.
OP is saying it's 2007, so I'm pretty sure there's no pins. Our 2002 doesn't have them. There's still an extra hole but I haven't figured out what Ford meant it for.