trinary switch on top of drier for electric fan

[bsa_bob2]

Can anyone tell me if i HAVE to have this trinary switch, i have vintage air, With a chrome drier,It has a 2 wire switch on the top of it Is this the trinary switch?"Or do i need to install a different one? on the drier. What does it look like" i am finding out , it should be installed to compensate for the electric fan ??i installed recently. if you can't help please refer me and thank you bsa_bob
any help would be very appreciated

[bsa_bob2]

thank you Denny i do appreciates the help Iwill take a look bob s