Check under the dash (probably passenger side) as there could be a split hose causing the problem. On older vehicles the condenser unit is behind the passenger dash and if there is a problem with the operation of the condenser it so,metimes leaks water (not air con gas/fluid you'll be glad to hear!) into the passenger footwell.
One quick fix would be to extend the problem outside the vehicle till a proper diagnosis/repair can be arranged.
Kindest
Skibum