First, welcome
@rayblank. Not familiar with that brand, is it a Harbor Freight brand? If so, you may not find the exact part. But do try ereplacementparts.com. If it's a rocker switch, you may be able to find a substitute. If it has electronic speed control, it could be that circuitry is fried, in which case, finding the speed control will be looking for hen's teeth. You could skip the switch, wire directly bypassing the switch and putting an inline switch on the power cord. If it won't run after that, then it's most likely the speed control module. Some routers have built in fuses, be sure that if you have one, that you make sure it's not blown.
Ebay sometimes has odd parts like this, so do a search there.