This has been happening lately, i was driving one day i tapped my brake not bard and my ABS light came on. gave me a ? i touhed my brakes it has hard as a rock and a very loud noise was coming from what i thought was the caliper. It wasnt a frozen caliper, infact the calipers wernt even engaged. Now it has happened 3 more time and heres the big part it makes a ticking noise coming from around the master cylinder, its pretty loud this happens WHEN THE CAR ISNT EVEN ON! my keys wernt even in it. I unplugged th battery, i am completely puzzled on this. Someone plase help me. the sound goes on and off, some days it wont even happen. i dont want to drive it but i need to get to work some how. car only has 103,000 miles. 4.6 V8 if it makes a difference.

 

Brake fluid slowly evaporates over the years- have you checked the fluid?

 

I would try unplugging the ABS module and drive it to see if the problem goes away. You won't have ABS and the ABS light will be on but you will at least know the source. Might have a bad ABS module or wheel sensor.