Mouse cursor goes crazy!
unfortunately I´m experiencing the same thing since yesterday.
I don´t even touch the mouse  but the mouse keeps moving in a 3 to 5 seconds interval.

Did you proceed with this problem?

What I found so far:
- It is not the mouse (Magic Mouse) nor Bluetooth. Switching off both doesn´t change anything.
- It´s not in my account. Switching to another account is not the cure.

I´m really embarrassed, but I solved the problem here.

Yesterday my mouse battery was empty and I connected an old microsoft mouse with a cord because I ran out of loaded batteries. After reloading batteries I continued using Magic Mouse. But I didn´t disconnect the cord mouse but put it into a box. And since than I had tis problem. Removing the cord mouse solved the problem.