I have 3 light switches in my home that can control up to 8 (or 9?) ceiling lights through out the house. They have a rocker switch on the left side and a knob on the right side that goes from 1 to 8 (9?). They control the kitchen, hall, a bedroom, laundry and side door lights. Do they have a particular name? I drew a picture of what they look like. I need to buy a cover for one and a knob for another.