interior lights on by themself., what is causing this? Options

[Crzybakerdog]

it seems that the problem is that when it is raining and the car has collected water that something that is suppose to drain out excess water is backed up and that it causes the cars interior lights and air conditioning to turn on by itself without the key in the ignition. where should i look to find out where this backup is being caused. my guess is that it is where the drivers side door is or where the below the wipers are the drainage for that could possible be clogged and i need to find out where it is. has this happened to anyone else ever since they had their celica.