My fog lights come on by themselves?

This is most likely due to a switch failure if the fog lights are the only ones that are affected. There is a separate switch going from the headlights switch to the fog lights so I would suggest unplugging the switch and if the lights go out then the switch is the issue. The reason is, you are removing the power from the circuit and the lights go out. If they stay on then the short is further down in the system.

Here is a guide that will help with testing this if you just want to use a test light so check the system for power:

https://youtu.be/Hlna_kUt7As

Below you will find the wiring diagrams that will help with this as well.

I also attached a repair from the same vehicle but was on the community forum of the online service manual. As you will see they replaced the switch and it fixed it.

Please run through this material and let us know what you find. Thanks