GE garbage disposal

My brother-in law installed a new GE garbage disposal (Sorry don’t know MN#) and it’s running backwards. It’s the type when you insert the stopper it runs and remove it and it stops. Well it’s working backwards, when the stopper is removed it runs. It stops when it’s installed. I’m going there tomorrow to look at it. Is there a NO or NC switch on this type of disposal? :confused:
Any idea’s ?

Thanks
Mike

Just wanted to let everyone know the problem was solved. It had to do with the button that engages the disposal. They weren’t engaging the stopper properly.
Thanks
Mike