Phospors and Phosphorus
Phosphers have never been made with phosphorous just like lead pencils have never been made with lead. The words have a common origin but there is very little chemical relationship.

Phosphorus is a Latin name for the planet Venus and, figuratively, for any glowing object. Early chemists in the 17th century used the word to refer to any substance which glowed spontaneously or when heated. They characterised and named several different types of phosphoruses. When the element phosphorus was isolated from urine in the late 17th century it was called “English Phosphorus” or “Phosphorus of Urine” and later simply “Phosphorus”.  

The older meaning of “phosphorus” and “phosphor” continued into the 19th century and, in the early 20th century, “phosphor” began to be used with more scientific rigor to refer to a material exhibiting phosphorescence.

Phosphorus (the element) is not phosphorescent; it emits light only insomuch as it spontaneously ignites in air.

Graphite (a.k.a. plumbago) was used as a substitute for black lead hence it was the "lead" in the pencil.