brakes squeeking and now the brake light on the dash is coming on

RedFish said
The linings and wear dust in a drum can absorb quite a lot of brake fluid before the leak appears on the outside. Saturated linings cause a squeak also.
if you just repeatedly add fluid until you have evidence all over the backside of a wheel you will have a real mess to clean up on the inside of the drum.

I put more fluid in the master cylinder and low and behold, it is much better. This leads me to believe that it most likely a leak and not a master cylinder. I have access to a hoist and will check this out later today/tonight and report back. Thanks for help.