Touch Screen Issues?

Hi, my phone is acting really strange. It has been for a while, but now I have decided to see if I can fix it. The screen will sometimes become super sensitive, as in if you try and scroll down a page, the screen won't accept the scroll, just click on what ever your finger hit first that you were supposed to be scrolling over. It also will take one tap as 2 or 3 say when typing. And very occasionally it will touch things I did not. It only happens once in a while, and oddly I have noticed it seems to only happen at night or in the evening ?