Brake Pedal Click

I have a 2002 Hyundai Santa Fe with 152,000 miles on it. Last night, when I got in my car after work, I noticed that the brake pedal is now making an audible click when I press down on it. This has never occurred before (including on my way to work yesterday), but is still doing it today.

No lights are present on the dashboard, and I have not noticed any difference in the performance of my brakes. Does anyone know what could cause this, and should I be concerned?

More than likely the brake light switch is making that noise.
Have somebody check that your brake lights are still working when you push down on the pedal.

That same switch can also work in conjunction with the lock mechanism on the shift lever, so you should also verify that the shift lock is still working as intended.

If both your brake lights and the shift lock mechanism are still working properly, then this is not likely to be something of a serious nature, and you should be able to defer any action until the next time that the vehicle is in the shop for maintenance.