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

Definitely not a safe condition. Don't drive before you fix, please. The light is coming on when you brake to indicate an extremely low fluid situation. I know it seems kind of stupid to have a light that comes on to say "The brakes aren't working properly". Like you haven't figured that out already. But there it is.

You didn't say if you had drums on front or disk brakes. Check the inside of the rim and tire looking for oil. Finding oil will indicate a failed wheel cylinder or caliper piston seal. Neither is a big deal to fix, but things won't improve until it is fixed.

You should also clean the drum or rotor to remove oil residue. Because the lining of the brake pad or shoe has been contaminated, I'd recommend replacing the linings of both brakes on the axle.