Good Morning Harold:
Thanks for the pix! I remember seeing an old rotary switch (pic No. 3) exactly like this, just inside the door to the boiler room in my aunt's house about 25 years ago. It had a hand-lettered sign thumbtacked next to it, labelled "oil burner switch" (or something like that). I assume this must have been some sort of emergency shut-off in case the burner got out of hand...? [Linked Image] I have a number of these old rotary switches in my collection of vintage electrical devices.

I have seen switches of the type shown in pic. no. 4 for sale on eBay at various times. Do you know if this kind of switch was used to control lights, or could it have been used for something like an electric hot plate element?

Mike (mamills)