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That sounds like your brake light switch is out. There is a switch at the top of your brake pedal, this switch is depressed by the pedal to send signal to the brake lights. This is what turns the brake light on/off. This switch also tells the car that it is safe to switch out of "park". If this switch goes out, the car will not switch out of park.
Follow your brake pedal all the way to the top and you will see this switch.