Yes the TouchScreen (digitizer) can be disabled, but I would not recommend it, there are many ways, disconnect the digitizer flex ribbon cable, using catnip to modify the calibration so it does not see the digitizer (force a software disconnect), using stop hidd (which disables the keyboard/volume/power etc...).
Originally Posted by MartinH@webos
Best way is to fix the problem, if battery replace battery, if digitizer is dirty (oils/water/soft drink/dust) clean it, if flex cable has gotten pulled, then disconnect/reconnect (seating in the channel connector is very important).
Some times I have seen the devices (Pixi Plus/Pre Plus/Pre2) get hot enough where the taps show up like ghosts, adding a good screen protector might help, but then I have seen even with Screen protectors some of them (even good ones) removal of the screen protector solved the ghost taps...
Really the solution to this problem has many solutions and which one will work on your device is trial and error at best.