If your wipers have a mind of their own it's usually one of the following:
Intermitent (pulse) wipers - the module is probably bad. It's under the steering column and is accessed by removing the plastic curved trim piece. It is a struggle to un-plug from the harness and be careful when sliding it out of it's mounting clip. The tabs break easily.
If you have a tilt steering wheel - a ground/short in the wiring that runs up between the casing and the shaft is probably the cause. To check, try tilting the steering wheel all the way up (or down) and see if the problem goes away.
The first fix is easy - change the module.
The second one - not so easy. To find the problem and fix the wiring, you will have to pull the steering wheel, dismantle the the column including ignition, hazards, multi-function switch, etc.
Also, try washing the hell out of the inside of the column with a lot of CRC.
Or, if tilting the steering wheel way up or down solves it, get used to it.