Well the bulb could have broken a long time ago and disposed of.
As for electrical devices, it is the parts that make the whole and the parts are individually recognized to be parts of a possible circuit.
To me it looks possible, i once build a radio in high school and all the parts are simple (except for the transistor maybe), some wire a few nails, resistors, transistors, a diode and a you can build a receiver. An electrical circuit is comparatively much easier to build.
This does not mean that Egypt had an electrical age when the pharaohs reigned, but only that it is possible that at one time they had a (just one maybe) system in place that did something with energy.