Air conditioner leaking in passanger floor boards how do i fix it

Could be the drain tube is partially clogged. It is usually located on the fire-wall or down towards the floor pan under the car. It is usually close to where the A/C lines go thru the fire-wall. About 1/2 inch diameter sticking straight out but may have a 90 degree elbow pointing down.
Also, its been extra hot and humid all over and moisture could be freezing inside the unit when on MAX A/C, then suddenly melting when switched to normal. This opens the outside air door and allows warm/hot air into the unit instead of recirculating the cold air inside the car. The drain may not be able to handle a large, sudden quantity of water.
Perform a "driveway" test. Open the hood, start engine and run the A/C on normal with the windows or doors open. Locate the drain tube by looking for water dripping. Once located twist 2 or 3 pipe cleaners together and verify the tube is clean. Then close the doors/windows and switch to MAX A/C. Check for water dripping. If it stops dripping, water is freezing inside and now you know why!