your over flow is clogged thats why you are leaking in the house use bleach to unstop it as far as not cooling your filter and your coils are dirty……………..go to home depot and get a coil cleaner for 6-10 spray on coils let sit 20 minutes then rinse off let coils dry 2 hours then turn a/c back on …….in mean time replace or clean the air filter this should work if not then call the repair man

Knowing which air conditioner to choose will help keep the cost down. Get the facts…

Have you kept the filter clean?Have you been pouring bleach down the drain hole of the drip pan? Are coils and drip pan clean?

You need to give more info than that… is it a window shaker? Sometimes when you use them for long periods you have to shut them down for a while to defrost because the coolant actually freezes solid in the plumbing of the unit. This could also contribute to the condensation leaking into your house. Make sure the unit is level as well.. condensation should normally drip out the back of the unit to the outside of your house.