Pardon my stupidity,how do you vote for someone for Speaker who isn’t even a member of Congress?
the constitution allows it
To answer your question, there is no Constitutional requirement that the Speaker of the House be a sitting member of Congress.
There is no legal prohibition on a non-member of the House serving as Speaker.
You vote for a named individual who isn’t a House member the exact same way you vote for one who is.
Because any adult American citizen is eligible to serve as Speaker of the House.
I could be mistaken, but I believe in theory the Speaker of the House can be any US Citizen. It doesn’t necessarily have to be a member of the House.