Toggle Switch with Nuts and Lead, Singer Featherweight (Vintage Original) fwtheme scroll through and you will

scroll through and you will see that the top arm of the attachment fits in the presser bar slot at the back of the machine

The box has its end flaps which is rare with these 75+ year old attachments

allowing either screw to screw in to the hook assembly

At this point there should be a slight pull on the thread to indicate that there is a minimum tension

Toggle Switch with Nuts and Lead, Singer Featherweight (Vintage Original) fwtheme scroll through and you willVintage original toggle light switch complete with both thumb nut, lock nut and lead. This was taken from an original Singer Featherweight 221 and part is in good working order. This style will only work on Featherweights that have the light switch on the base of the machine rather than on the light itself, like later models had.