create a blueprint and add the mesh, particle and light, place the blueprint in the world where you want them. to change them all globally, you just edit the bp from the content browser and it will propagate through to the others as the new default. you can also then click on each individual one in the world and adjust the properties for just that on in the details panel if you need to, but this is considered an override, thus it wont follow the global setting until reset to default basically it works the same as a material instance, just with actual actors.
from there you could look up simple node snippets like flickering lights, add it to the blueprint, and it will go to everyone