Ghost touches on the right side of the screen

I'm having a ghost touches on my screen for about a couple of months now. If you check the screenshot you can see the touch indicators (I wasn't touching the screen at all when I took that screenshot).

And before this screen issue, the phone was pressing power button by itself. Force restarting the phone continuously. That problem is gone and then this problem started.

Since the power button is on the right side of the phone and this screen issue also happening on the right side of the screen, I'm curious if they could be related. Maybe some dirt got inside or something?

I would be very grateful if you can tell me if I need screen replacement or I can just disassemble my phone and clear that side on the inside. I know it's pretty old phone but I grew very fond of it.