Welcome and thank you for allowing me to assist you! If they are stopping in the middle of the windshield at times, then I am leaning towards the wiper motor itself. If it were a fuse, then they would not come on at all. If it were the switch or control module, then they would not come on at all or would stop in the parked position and not in the middle of the windshield. Try this: when they act up, manually try to move the wipers by hand to get the motor to go again. If it does, then have the wiper motor replaced.
I hope this information helps, and let me know if you need further assistance with this.