Ghost Touching

(1) Try and Force Restart your iPhone EXACTLY as shown below and see whether that resolves the issue:

• Press and quickly release Volume UP button
• Press and quickly release Volume DOWN button
• Press and Hold the SIDE button until an Apple logo appears and then release the Side button (Can take up to 20 seconds. (DO NOT release Side Button when invited to Slide Power OFF). 

(2)  If the above does not work then - Ghost touches are the first indication that the iPhone display is failing. If you have a screen protector on it then try removing it along with the case and see whether that resolves the issue. If not then get your iPhone examined at the Apple Store or at an Authorized Service Center.

Axel F.

In addition to Axel’s advice:

• If it only happens when plugged in you need a new cable
• There is a defect in some iPhone X models, and Apple has a recall for them: iPhone X Display Module Replacement Program for Touch Issues - Apple Support