If you fear your opponent potentially destroying a Continuous Trap Card that you Set (which is currently in your hand), you can Set this card as bait. Once your opponent attempts to destroy this card, you can Chain this card by discarding the Continuous Trap Card you would have Set, and Set that card as a result.
Use this card to set "Call of the Haunted" by sending a powerful monster to your graveyard. This way, you can summon it faster.
In a Spellcaster deck (such as a "Dark Magician" deck), use this card to recover a "Magicians' Defense" in the Graveyard. That will allow you to immediately halve all damage (if you control a Spellcaster) that you'd take, since the set "Magicians' Defense" can be activated right away, and when it's sent to the Graveyard again, you can revive a Spellcaster.
In a "Numbers" deck, use this card to retrieve "Number Wall" that was previously destroyed to safeguard your "Numbers" from destruction once again.