Easiest way to create electric light source from scratch
Carbon arc lamp is probably the most low-tech kind of bright electric light. You need only carbon rods (welding equipment or extracted from common zinc battery cells for example), large resistor and somewhat powerful power source. See for example description here.



(Image from this site)

But be really careful if you try to reproduce this kind of light source yourself, it is quite dangerous for various reasons (fire danger, high voltage, production of strong UV light and noxious gases), see the warning in linked text too.