My screen is ghost touch

While Jhon's suggestions are an excellent way to start and well worth trying, in my experience the ghost touch phenomenon is most commonly caused by damage to the digitizer. There are delicate connections between the ribbon cable connected to the digitizer and the circuits printed on the glass, and when those connections get disrupted you end up with electrical noise being introduced on the signal lines. The motherboard receives those bogus signals and tries to interpret them as touch inputs.

Unfortunately, it's not practical to repair those connections, as it requires specialized equipment and expertise. So for us normal human beings the fix is most often to replace the screen, giving you a new digitizer that will resolve the issue.

I was unable to locate any iFixit-style guides to that repair on your phone, but I did come across a YouTube video that shows the procedure in fairly good detail.

STILL VERY EASY TO FIX? ASUS ROG Phone 3 Screen Replacement - Sydney CBD Repair Centre - YouTube

Hopefully that's everything you need to know. Good luck and let us know how it all turns out! Feel free to ask if you have any questions.