I have been wearing ear plugs for years (the soft spongy ones) with no ill effects. Changing every few days is important, as others have said, to prevent the possibility of infections. I am a very light sleeper, too, and have gotten to the point where I can't sleep without them. DH occasionally snores, but he also breathes loudly and that's enough to keep me from falling asleep.

I don't think you have anything to be concerned with as long as you're careful inserting them and make sure they're clean. A good night's sleep is so important!