A/C leaking water

This is my wifes car, she just told me about this, and it has been going on for a month or so. When the A/C is on water builds up on the inside of it and drips out on the pass. Side up by the fire wall. If you turn left water will fall onto the fan and a make the noise of water hitting a fans while the water drips out below of the fan motor. I know there should be a drainage hose that takes the water to the outside of the car, but I can not find it. I think that hose might be cracked or clogged or just fell off. Would this be my problem or might it be something else? A/C