I don't have a rechargeable aid myself, and I'm not sure if there's any sort of on/off switch on the silver part. Mostly though, if the light is showing, it means that the hearing aid is ready to go.
The grey plastic bit that goes in the ear canal needs to be cleaned daily. Just a wipe over to make sure that the small holes at the bottom of it aren't clogged with ear wax or any other debris.
It wouldn't harm you to place the dome very close to your ear canal without actually placing it right in your canal - you would probably be able to hear some sort of extra sound coming through it.