My brake light will come on in the morning for a few minutes but always turns off after a mile or so. Emergency brake is un-engaged and jiggling it doesn't turn it off. The brakes work perfect. The last time the brake light came on I had a leak in one of my lines and it was obvious that my brakes were going out.
About the only issue I have are pads that are wearing out (squeals when I stop) but I don't think they are connected to to the brake dummy light.

Any ideas?

 

may be a stupid answer, but you didnt say you checked your brake master cylinder, make sure that is topped off with DOT 3 or 4

 

The more the pads wear, the further the piston is moved out, thus the less fluid in the master cylinder if its not topped off. If you replace your brakes, you will not have a light issue anymore as you will have to push some fluid back into the master cylinder.

btw there is a sensor in the master cylinder.

 

I checked the master cyl and it's right at the min line... I guess I'll top it off here today and see what that does...

 

Top it off to the Max line, the sensors are really senstive in Toyotas. Low brake fluid is the most common cause of a brake warning light.