Just a bit of info re: Ford truck fires.
Ford had a significant design/manufacturing problem for a number of years with the design of its F-series and E-series pickups and SUVs (Expedition, Excursion, Navigator) that resulted in a large number of vehicle fires and a huge recall. The issue was an always-on switch in the cruise control. It was located in the engine compartment near the firewall. Ford's system had power always-on to the switch, via direct battery connection, even when the vehicle was not running, switched off, parked, what-have-you. Exposure to corrosion resulted in eventual failure of insulation at the switch and a fire would result. The most devastating of the fires were unattended, overnight events ~~ usually in driveways near houses or inside the garages, both of which often caused house fires.
To their credit, Ford worked hard to replace the switches once the issue was identified.