Every time I plug my charger in, my phone spazzes out.

My phone is fine. No cracks on the display, I got it fixed almost two months ago. About a week ago, it got really hot and when I would press on something, it would press on a billion other things at once. It especially does it if I press on one side of the screen. It goes absolutely mad and it’s also driving me mad as well. I noticed it’s only when I plug my charger in.

Why is it doing this? I’ve had this charger for months. My phone also starts to heat up quickly on the charger and it’s never done that til recently.