The word ghostwrites is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 18
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (38 words)
egoists, egotist, ghettos, goiters, goitres, goriest, gothite, growths, hitters, hogties, hosiers, ogreish, reshows, resight, retwist, rosiest, showers, showier, sighers, sighter, sitters, sorties, stogies, stories, swisher, theists, thirsts, thorite, tighter, tigress, tithers, twister, weights, whitest, wishers, withers, witters, writhes