bad master cylinder
Under the hood. Drivers' side attached to the brake booster on the firewall
If you follow the brake pedal up under the dash, you'll see the switch where the actuator arm from the brake master cylinder attaches to the pedal.
You have to remove the Master Cylinder, disconnect the rod that is connected to the brake pedal and remove the bolts holding the Power Booster on. Connect in reverse order.
May be the proportioning valve by the master cylinder
You have to remove all the hoses etc. from the top of the engine and on the drivers' side you have to remove the brake master cylinder so the cover can clear, it takes time and it's a pain to do, good luck.
Eight, one for each cylinder
You used the term wheels I am guessing you mean more than one wheel. Check the brake fluid. If someone, anyone put oil in the master cylinder reservoir your in trouble. Engine oil / mineral oil will swell the rubber parts in the hydraulics of your brakes. Remove the filler cap on your master cylinder, stick your finger in the oil as far as you can get your finger. Stick your finger under running tap water. Brake fluid will rinse clean engine oil / mineral oil will remain oily.
cruise control switch
Save yourself some grief and take it to a repair shop
in the panel located on side of dashboard open drivers door to see it
If you mean the brake light, you just have to change the bulb or bulbs.