I have an old ceiling fan that has a three way pull string switch which is working properly(1. off,2. High, and 3. current to a rotary speed control switch). The speed control switch is broken. I have not been able to find a new switch as there is not a manufacturer's name on the switch, however it has several numbers. They are 137(underlined), 8145, 5017-0003-000. Can anyone tell me where to find a replacement switch?