Why is my left analog stick from my controller acts weird?

Question

When I was playing a game on Steam with my controller, the left analog stick is acting weird, even when I was not moving the analog stick. The input happens automatically, and it is not my fault. The left analog stick is acting weird that it is a problem to me. I need a help with this issue.

Update:

The controller that I have is a PlayStation 4 controller.

Answer 1

It's called stick drift. A quick solution would be to blow into the left stick.

Source(s): https://www.youtube.com/watch?v=7dVhU1dLmac