Every now again I have seen a wet spot on my driveway and if I squirt it, it behaves like brake fluid (makes suds almost like soap). Then I started noticing my Brake light coming on when accelerating from stop and then shutting back off. I assumed that behaviour of the light designates low fluid. Filling it seemed to cure it so then I confirmed a leak. It looks like its coming from this small metal box below where the master cylinder is, right by the drivers side cat. It has a few metal brake lines going into it and a wire plugged into it, like a sensor. It seems to be leaking around the sensor. Can someone explain what this is and what is likely wrong with it?