Does anyone know what to do when their mac trackpad goes haywire?

I've been dealing with it for weeks now. My cursor is jumpy and has a mind of its own. Sometimes it's fine, other times it's out of my control. It opens programs without my asking it to, it looks up words I type/read with an in-browser dictionary I didn't even know I had access to. It zooms in and out on the page I've got open. When I want to left click it right clicks (dictionary just looked up "klicks" for me, thanks dictionary). I tried wiping it down with a lightly dampened cloth to see if there was sticky on it but it's clean now and it's still rambunctious.

Anyone had this problem before and know what to do about it? If not, can someone please crosspost this to a place where lots of people know stuff about this kind of thing? It took me three minutes to get my cursor over the "Save as Public" button, please help me!