I know that the emission of light is evidence for a chemical reaction. However, are there any instances where emission of light can also be considered a physical reaction?
Most light doesn't result from chemical reactions
While there are many chemical reactions that can emit light and many related reactions where the emission is related to chemistry (for example the light from some flames is caused by electronic transitions), most light you see isn't.
An incandescent light bulb emit light because of black-body radiation produced because it is hot (this is not normally though of as having anything to do with chemistry). Fluorescent tubes emit light because of electronic transitions in gases or phosphors (both of which might be considered closer to chemistry because they involve electronic transitions but not the sort that indicate a reaction as they are entirely reversible). LEDs are similar.
A well set up Bunsen burner emits a small amount of light from the chemical reactions occurring in the flame but most well-regulated flames don't emit much light. A candle, on the other hand, has a relatively bright flame. but most of the light comes not from chemical emissions but from the incandescent emission from small soot particles produced from the (deliberately) inefficient burning. Ultimately that heat come from chemistry but most of the light comes from the basic black-body physics of hot objects.
So, in short, most light is physical not chemical.