It's seriously funny how freaked out people get from garbage disposals.
They're quite safe. They don't have spinning blades. They have something closer to a dull grater and arms on swivels that catch loose food and push it against the stationary grind plate.

You shouldn't put your hand in one because the little weighted arms are going very fast and could hurt your fingers if they got hit, but it's unlikely to push them into the wall.

They're great if you have proper sewage treatment, since it keeps the trash from getting stinky and it basically just gets turned into fertilizer like a more efficient, roundabout compost heap that I don't need to remember to poke.