It's aftermarket. Probably to detect a collision and notify the dispatcher like OnStar.
Exactly, if it were a Ford part, it would have an engineering number on it. Plus Ford usually incorporates their G-Force sensors into the 14B321 airbag control modules. It could also let them know if there was any type of impact that would put the vehicle down for an inspection or additional maintenance. For example we do a lot of CHP cars and one of their policies is anytime a vehicle is involved in a high speed pursuit the brake fluid must be flushed.