A stunt I pulled two sessions ago.

METHOD TO GET RICH: Resurrect people suffering from brain death.  Use necromancy to rebind the spirit of the original owner of the body back into their brain with a duration of mortal lifetime.  The body already has a heartbeat, so no need for an artificial one.
Become the most expensive doctor in the world. 
WHY IT WON'T WORK: They can't get wet.   
STORY IDEA: Alistaire Grey is a wizard with a talent for reaching across the barrier between life and death, but has never used it to hurt anyone or bind a human spirit.   He encountered a man who had been dosed with a massive amount of MPTP. http://en.wikipedia.org/wiki/MPTP  In trying to track down the culprit who administered the drug, Alistaire theorizes that he may be able to temporarily restore some semblance of movement to the man by binding his soul back into his body.  When he does so, and procures an identity of the culprit, he can't bear the disappointment of the man when he tells him that the cure is only temporary.   So he sets up a ritual to extend it for his lifetime, and tells him he can't ever take a shower.  "Shave your head and use baby wipes."

There's so many ways that this can go wrong, it would be impossible to list them all.  But here are some ways.  I would be fine with my GM using one or more of these.

White Council finds out about this EXTREMELY grey area. (Kinda boring, but pretty likely.)
Alistaire starts hanging out in hospitals ready to shove trauma victim's spirits back into dead tissue.
A living subject suffers a heart attack, and in the absence of the controlling heart beat eats their spouse/children. 
Unscrupulous Necromancers find out about this technique...
What else?