2012 Expedition XLT EL "Service AdvanceTrac" and ABS lights on

[Jermy-Jinky]

I have a 2012 Expedition XLT EL. The other day the "Service Advancetrac" warning appeared on the instrument panel readout and the ABS lights came on also. Then, for a brief second, I lost brakes. Then, the brakes started working again, but the lights stayed on. Later, after having been parked for a while, I went out again, and all of the lights were off. A few minutes into driving, all the same lights came back on, but had no braking issues. We parked for a little bit, then when we started back driving, same thing as before, all the lights were still on, and lost brakes for a moment. It sounded like the front driver wheel bearing was starting to go out (humming in right hand turns), so I replaced it with a new one. After replacing the wheel hub assembly, the lights went out. I took it for a drive and the bearing hum was gone, but as soon as i touched the brake pedal, the ABS kicked in like I had stomped on the pedal. It did this for about a mile, then all of the same warning lights came on, and the brakes went back to feeling like normal. The last time I drove it the other day, the same wheel was making the same humming again. The day I replaced the wheel hub, I also replaced both sets front brake pads. Neither appeared to be excessively or unevenly worn.
Also, I noticed when using the turn signal, sometimes you can hear it "clicking" inside like normal when they are on, and then the "clicking will stop, but the turn signals are still flashing. I've been looking and looking and have seen that it could be the steering rack, or ABS unit, or wheel sensors...are these things that are a major PIA to replace or repair? Is there something else I might be missing? Is there something I can test or check before tearing it apart or dropping hundreds into it? or worse, taking it to a shop?
Any ideas?