Now it's not so easy to experience no light whatsoever, to be
light-free.You could try deep underground.
If you do go
light-free, or at least it is quite dark(an underground cave or just the cupboard under the stairs), then take a luminous source (a torch!) with you. Use the torch to detect that lost ball by reflecting light off it. Shining a torch beam on a ball (or anything else) makes it a non-luminous source.