Phantom/ghost input on ThinkPad X220 Tablet touch screen

[the undecided]

For a couple of months, the touch screen of my 2012 ThinkPad X220 Tablet produces some clicks on its own. This is annoying to dangerous as it can just trigger any action. As of now I have disabled the touch screen via software on Linux, but it still is annoying. This looks like a hardware defect. I just wanted to ask whether you have any idea whether this can be fixed without hardware replacements.