trackpad going crazy

Every time I clean my macbook, even after turning it off completely off, the trackpad will go crazy, it will start opening things and closing things. This has happened before, but the mac was still under apple care it is no longer under apple care and I'm not looking forward to pay a lot to replace it. It is working now after months of non-use. Even when using the magic mouse, it would not stop the problem. Is there a chance that I am cleaning it wrong and how could i prevent this from happening in the future? Thanks -Darby