How Can I Fix a Glitchy Screen?

I have an LG-MS770 MetroPCS phone running Android 4.0.4 . Recently it's been doing some very strange and annoying (although sometimes rather funny) things with the touch interface.

For some reason (and for no foreseeable circumstance or combination of conditions) the bottom part of the screen and the 3 user "buttons" act as though they have been touched and glitch all over the place. It's not due to the presence of hands or anything, as when I unlock it and put it on the table and step back, it still clicks all over the bottom half of the screen. It's hard to describe what exactly it does, other than it's like several phantom fingers click all over the bottom part of the screen in bursts of activity every now and again. It's not a constant effect, but rather it happens every few seconds or so and lasts for anywhere from 1-3 seconds. I've tried restarting it, pulling the battery, charging it while on, charging it while off, and etc.

The only thing I haven't done is to reset it, which I would like to refrain from doing unless absolutely necessary. The interesting thing is that it had this issue a while ago, but I reset the phone and it was fine. But now it's started acting up again (same as the first time). My only theory is maybe that it has something to do with changing countries or maybe just running it for 2 days without charging (it was only on 25% when I did charge it so I thought it was good). I would say maybe it's the country thing, but that wasn't even a factor the first time it happened, so I think it could be ruled out. No new apps have been installed, and nothing new has changed in the phone itself before this happened.

Either way, does anyone know how I can fix this glitchy screen?