Boo!  Well, not boo, but our 
Happy Little Stampers CAS challenge does involve ghosting.  There are a variety of ways to do it and just as many definitions of what the technique entails so check out the tutorials and give one or two or three a whirl.
I am so into all things nautical, both above and below water, right now so immediately thought I'd CASE a card we made in a 
Julie Ebersole class at 
Impress a couple of months ago (Tonya took the pic below of her version from class--so cute, right?).
I masked off the front panel and sponged it with DI Salty Ocean.  I like the different shades of blue--like sunlight reflecting off the water.  For the ghosting, I took my HA Waves background stamp, spritzed it lightly with water and pressed it over the entire panel.  It didn't look like it had worked until I gave it a little blow with the heating gun.  Wowza!  Love the effect.  The sailboats are die cut from gold foil cardstock and a red gelli print. 
The Details:  Memory Box Marina Sailboats, Hero Arts Waves 
Background and navy shadow ink, Altenew Birthday Greetings, Distress 
Inks Salty Ocean, Recollections 110lb white cardstock and gold foil 
cardstock