My macbook built-in keyboard is going haywire. Does anyone know about a software workaround?

My 3-yr old macbook built-in keyboard is failing, and I believe it’s mechanical. The keyboard will occasionally hold down a key like ” over and over whether or not I have pressed that key. I have a USB keyboard to hook up, but, it is a little bit tricky to use a computer that has a mouse held down or a certain key at an awkward time. I’ve got finals coming up and papers, etc. and so I wondered, Is there a software solution that can turn off all input to my built-in keyboard? That would be really cool. Thanks!!