Dremel, since purchased by Bosch, has discontinued producing some on/off replacement switches for some Dremel rotary tools manufactured over 25 years ago.
Kauffman Family Tool had 2 NOS switches in stock and emailed images of both to confirm their correct application. From where I'm sitting no other online company carried this particular rare switch.
Kauffman Family Tool runs an essential business the way most American companies used to operate long before computer algorithms changed the business model and eliminated the emphasis on customer service.
Suffering the humiliation of dealing with a dehumanizing monolith like Amazon is no longer required. Kauffman Family Tool Repair now has that power and it's doubtful Amazon will ever come close.

I cannot thank Kauffman Family Tool Repair enough! I needed two small parts for a Delta table saw and while they did not have them in stock, I feel like they dropped everything to try to get me these parts as quickly as possible. Other national retailers said it would take about a month to special order the parts, but Kauffman was able to source the parts and get them in my hands in about a week. Kellie stayed in constant contact with me and even followed up after I received the parts to make sure everything worked out. Despite being a relatively small order, they made me feel like their most valued customer. I’ll definitely go straight to Kauffman for any service or parts needs in the future!