Prius V Brakes Clicking

I have a 2013 Prius V that is just about to hit 2,000 miles. Hardly driven. I don't know how I haven't noticed it, but when I apply light pressure to the brakes, even when the car is not even on, there's a click from the engine compartment. I can hear it in the car and outside of the car. "Click," like an actuator or switch of some sort. It happens when the car is moving or the car is dead stopped and off. If I press extremely lightly, the tail lights will come on. A little more pressure, but still very light, the "click" occurs.

Is this normal? I'm stumped at why I drove this long and never noticed it, which is making me wonder if it's a new noise. Granted, I've been driving without the radio on recently.

 

I found this, which described the exact problem I'm having. I'm curious if others hear this click as I can't tell if it's normal. But it's certainly annoying.
Clicking sound is made when brake pedal is depressed | PriusChat

 

I would just appreciate it if someone can tell me if their Prius V also clicks from the engine compartment when the brake pedal is depressed.

It looks like 1 vote above for only when it's off, which is different from my situation in which it always clicks, off or on, driving or not driving.