Anyone know how to deal with a crazy mouse on a dell laptop?

So this just started happening recently, but I have seen it on other laptops as well. My mouse (or pointer or whatever you call it on the screen) kind of floats around and sometimes I have no control over it and can’t even click on anything. So far it always goes back to normal at some point, but sometimes I have to shut the computer down. It is getting worse each day. Has anyone else experienced this and is there anything I can do? It’s a dell inspiron 4100. Would getting an actual external mouse even help? I have both the little square pad below the keyboard, as well as the little “dot” in keyboard, but when the thing is haywire, neither one works.