How to disable built-in keyboard and trackpad? after a recent drink spill on my MacBook, the keyboard is producing all sorts of random keystrokes and odd behavior such as holding spacebar, shift or arrow keys etc. Yes, I know this question has been asked before, but I can't comment or bump any old question due to the low reputation on the site so far.

I am looking for a cheap way to disable the keyboard. Could one remove the keyboard ribbon from the logic board to disable it? I use my laptop in a 100% external mouse and keyboard environment, so I don't need the built-in keyboard to work.

I know there is somewhere to disable the trackpad in System Preferences, but I could not find anything.

Also, I saw the old way of getting to disable the onboard keyboard was by unloading a KEXT file.
Since you already know the software way, how about permanent removal (the hardware way).

Open it and unplug the cable. 

Find the instructions for your model on the ifixit web site.