There are pickups, and then there are pickups. Use the menu at the left to review your options in the following categories.
Acoustic (piezo and transducer) pickups
So you've already got a mandolin and you want to go electric without getting a new one. You've been through this entire site and haven't found the e-mando of your dreams. You'd rather slap some wires on your trusty acoustic than support one of the many fine manufacturers I've gone to all this trouble to track down.
I guess I might as well admit failure and slit my wrists—but before I do, I've chosen to offer you what you're looking for: information on all the pickup makers I know about. Shop to your heart's content.
With the exception of Steve Ryder, these makers supply mandolin pickups on a custom basis only. However, many pickups made for guitar—including the single-coil and blade designs here listed—can be used for mandolins because they have a one-piece magnetic element as opposed to individually wound poles. This eliminates the problem of matching the pole positions with the string spacing.