depending on what electromagnetism your talking of,
visible electromagnetism in which eyes detect things like Fireflies, light bulbs, and stars all emit visible light.
radio waves emitted by radio stations. Radio waves are also emitted by stars and gases in space.
Infrared - is like the vision that night googles that pick up the light emitted by things with heat.
https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html
