Alyssa Milano has signed on for a guest role on ABC's "Castle."
 
According to The Hollywood Reporter, Milano's character will be a former lover to Nathan Fillion's Richard Castle. The trade offered no information on when Milano's episode will shoot or air.
 
Milano's set to star in the ABC midseason comedy "Romantically Challenged," which now seems to have a logical potential home after the network cancelled Kelsey Grammer's "Hank." No premiere date for "Romantically Challenged" has actually be announced.
 
Most recently seen in an extended arc on "My Name Is Earl" (or in the stands at Dodgers' playoff games) Milano's TV credits include "Charmed," "Melrose Place" and, of course, "Who's the Boss?"