Where is the horse for the quest on horseilse

Depends what horse your talking about. I'll tell you a few locations for a few horses that you must find on quests, and I hope it's correct and it helps.

The horse that you need to find for someone in Appleton is in a forest north west of Appleton.

The horses you need to find for someone on Half Haven are easy to find. They are on the isle next to it, and you just look around for a bit. To get to that isle, you just take the bridge. To get to Half Haven, you talk to the person in the Shelton Docks.

Hope I helped, I'm sorry if I didn't, you weren't specific