Did you check the brake fluid? The light is connected to a float in the master cylinder. When the fluid is low the light comes on. If the Trac is moving and the fluid is close to low it will flash on and off as the movement of the Trac affects the float.
If the fluid is fine, it's probably the e-brake pedal. You don't have to throw it very far at all to engage the light, perhaps it's not all the way up....or there may be some dirt or something in the switch that's the problem.