How to sound-proof a bedroom for cheap?

My apartment complex was built in the 1920s and the floorboards upstairs creak like crazy when my neighbor gets up at 4am for work (and I can hear him snore)! I have drop panel ceilings and was wondering if I can stuff pink insulation in between the two ceilings. There is a light fixture in the middle of the ceiling, would it be safe if I leave space around it and the insulation or would it be a fire hazard? Are there any super cheap safe ways to do it?