Irratic mouse (cursor)

It has taken me about over 30mins to get here because of my mouse.

The issue first occured several months ago but only happened rarely, now I have good or bad days. Typing is a struggle! Unexpected highlights and deletes of letters not clicking where I want it to.

There's more.........When I log in and try to open Safari the cursor makes the icon go dark and when I move it the mouse it drags the Safari icon. So I have to wait and start again. Click on the icon any icon and when I do nothing happens or there is a big delay.

There's more......before I open any icon or use the Edit View or even File, the cursor makes these rectangular or square shapes on the screen (almost like when you cut and paste). When this happens there is no chance of opening Safari or any icon as it will drag then or not respond.

All this with new batteries in the mouse. Anyone had this experience with their unpredicatable mouse. Clicking to post this takes time.