Alice dies wearing a Ring of Mind Shielding and their soul enters the ring. Bob finds the ring and puts it on, but does not attune to the ring. Can Alice communicate with Bob?
From the description of the item:
If you die while wearing the ring, your soul enters it, unless it already houses a soul. You can remain in the ring or depart for the afterlife. As long as your soul is in the ring, you can telepathically communicate with any creature wearing it. A wearer can't prevent this telepathic communication.
When Alice dies, their attunement ends:
A creature's attunement to an item ends if the creature no longer satisfies the prerequisites for attunement, if the item has been more than 100 feet away for at least 24 hours, if the creature dies, or if another creature attunes to the item.
If Bob is wearing the ring but not attuned, they gain only its nonmagical benefits
Without becoming attuned to an item that requires attunement, a creature gains only its nonmagical benefits, unless its description states otherwise. For example, a magic shield that requires attunement provides the benefits of a normal shield to a creature not attuned to it, but none of its magical properties.