Key in floorboards of Madell FF7?!?!?!?

when playing through the game for like the 10th time last night i stumbled upon a key next to the house across the walkway which contains the White Chocobo which you eventualy get the "Contain Materia" from. just left from the door ther is a an standing there and if you press the action button just behind him, there seems to be a key which is unreachable.

Could anyone tell me how to get this and what it does?

Cheers

Enter the house/shack just south from where the key is.
Examine the ‘door’ at the back of the house. You’ll discover it is locked.
You should now be able to go pick up the key.
Use the key on the door and it will break.
You have two options: whether to lie or be truthful.
Telling the truth rewards you with a Cursed Ring.

I think this is right. That’s all from memory. If not, someone else should be able to help.

Accessory Name: Curse Ring

Added Effect: [Str +35], [Mag +35], [Dex +15], [Vit +15], [Spr +15], [Luck
+10], begin battle with Death Sentence [100%]

Shop Locations: None

Accessory Purchase Price: None

Accessory Sell Price: 1

Yielding Enemies: Ultimate Weapon (Steal only during Mideel destruction)

Found Where: Mideel (examine the door in the shop, then pick up the Old Bent
Key on the creaking of the bridge, then go back to the shop and open the door
that you could not before)"