Mouse pointer appears in-game, what to do?

I often play video games on my PC and of course it annoys me when my mouse suddenly appears. I used to have a laptop where the problem wasn't there. But lately my mouse pointer appears in every steam game, after about 3 hours after my PC was activated. The problem starts with sound as if you were closing something, so I think it's because of the wiring. If I manually remove my mouse and then reconnect it, the mouse pointer is also shown in the game. Can you do something about it or do I have to create a new mouse or even completely new USB ports?

First of all, I would simply connect the mouse to another port and / or clean the contacts of the plug and socket (s). If that doesn't work try another mouse (a cheap mouse for 5 euro is enough) or try your mouse on another PC. (if possible)

It works on another PC, but unfortunately it doesn't work on mine. I wanted to buy another mouse as soon as possible anyway. Whether connecting to my USB 3.1 or 3.0. It makes no difference. I thought maybe of the driver, or of my PC power supply, because I have everything connected to a socket. I also noticed that if I hang my fan on the socket and turn it on and then immediately off again, then my PC makes the same sound and my 2nd screen goes black for 1-2 frames.

I don't think it's the power supply, but I can't guarantee it. You could, however, possibly unplug another component if this is possible. Otherwise, wait for the new mouse and try it, although I can tell from the answer that it is probably not the mouse.