The condensate pan is probably unlevel and running over into your duct. Another possibility is that the drain pipe or hose has become clogged with dust or has been kinked, preventing condensate from draining properly.
Water will condense in the inside unit of the air conditioner. This is because the coils in the unit get cold (ad expected) and moisture in the air condenses on them like moisture on a cold glass. There should be a drain inside the unit to drain this water. Check that it isn't clogged.
The only way to stop water from dripping through is to use some kind of a waterproof barrier. The best material to use depends on what is leaking rainwater.
fix the roof.
You have to replace the cartridge
You take the faucet apart and replace the washer and stem seal .
maybe maybe not
You take it apart and change the seals and washers.
the central vacuole
Washing doesn't stop rust to return.
re-level the unit,and/or clean the coil
Much emphasis has been placed on careful conservation of water and electricity. Many grand ideas are presented. Yet it is often the most basic maintenance that can provide conservation benefits. For instance, replace dripping bathtub faucets. There are many different types of bathtub faucets these days, and a simple replacment can save water immediately and money in the long run. Older homes are particularly susceptible to this problem. What's worse, an untended dripping faucet can ruin the veneer of an old tub or sink. Dripping faucets and stained sinks or tubs lower the value of homes for sale as well.
Water pipes may be covered with foam rubber to stop condensation dripping from the surface of cold water pipes in warm and damp climates, and to insulate hot water pipes so the water in them does not cool while flowing from the hot water tank to the faucet,