Bigby's Feeling Fingers
From Ardrana
Bigby's Feeling Fingers calls into existence a disembodied hand under the caster’s command. The hand cannot hold, grasp, or carry, but it does have an amazingly sensitive sense of touch. The hand’s sense of touch is so fine that it can note minuscule cracks, separations, or openings in a surface, and thus detect the presence of a secret or concealed door. The hand cannot be destroyed by physical attacks, but it is susceptible to magical damage. The hand can trip a nonmagical trap if the location of the trap is known.
Note: Bigby's Feeling Fingers originally appeared in the Greyhawk Adventures AD&D campaign setting from TSR. Its use here is for the purposes of providing context for the campaign only.