So I purposely killed a sim to make him a ghost and have her house haunted.Moved in my current sim, few nights later his ghost appeared, I clicked on him and the only option I got was "ask to pose"
Is there a fix?

Why would any ghost would pose after you just killed him?? I think he's really mad, you can't fix that.. he's an angry dead man

I had this problem recently, too, that my Sim was unable to interact with a haunting ghost. But I think that I brought this upon myself by resetting that ghost a few nights before.

I fixed this by resurrecting the ghost and then telling it to go back to the Netherworld. I did this with the "Oh My Ghost!" opportunity because my Sims was already best friends with the ghost and so received that opportunity a few days later anyway. Once the ghost was resurrected and part of the household I clicked on the tombstone in the inventory and chose the option "Go Back To The Netherworld". Once the ghost reappeared a few days later it was back to normal.

There are several other ways to have a ghost as part of the household if you don't want to go that opportunity route, because it requires you to have a high relationship with the ghost to receive it. An in-game way is to do it with the Philosopher's Stone reward you get after reaching level 10 in Alchemy and completing a three-part quest. A modded way is to use Debug Enabler. I think the option in DE is "Create Playable Ghost", but I'm not too sure at the moment. You'll have to try around and quit without saving if it isn't the right option. There are two or three more in DE.

Note that if you've been keeping your sims extremely happy, the Philosopher's Stone can also be purchased with a boatload of Lifetime happiness points.

(You can also use Master Controller to give the sim a boatload of Lifetime happiness points if you prefer...)

Moved to help!

Could it possibly be the way you went about it? If youre specifically wanting to kill somebody to get them to be a ghost than I'm not so sure about the interactions but if youre just wanting to have a ghost on the lot in general and aren't bothered by the method of getting them I think you can use nraas and go through CAS to get a ghost, maybe shift+clicking the sim as well and entering CAS, but there's also a sim transformer mod here by user Treeag.
Maybe the cheatsy way will render different results.

I'm pretty sure I'm not the only one who's done this.I needed a ghost for a story, but can not have him as a playable ghost(household member) as of right now.Which is why I killed him.I normally do not kill my sim

That could be it actually.I will have to redo it and see if I can do him a different way.It just kicked in that I used Disasters mod to kill him.

Edit: This time, I just had him starve, no mods used.Now he's haunting the house and he just came out I click on him with my current sim and all I get is "Ask to pose" and NRASS(mod)

I'm sorry if you misunderstood, I was joking in my reply if maybe your ghost was angry, I didn't know that in the game if one sim can murder another sim without the help of weapons mod, but as far as I know even with that weapons mod it didn't make the sim becoming a ghost and haunt the murderer, the sim that was killed with weapons mod just disappeared from the game, if you really need ghost for your story, you can create one from CAS to your household at the beginning of the game, or maybe it also doable by converting to ghost with cheat like when converting playable sim becoming to NPC, but still I don't know if that would make the ghost to haunt the living one.

You can see if making a ghost in CAS and then making the ghost unselectable with Master Controller will suit your needs.

Or you can go through the Game Problem FAQ http://www.modthesims.info/wiki.php..._3_Game_Problem to see where the issue might lie.

Unfortunately, it didn't work.I endded just going with the philospher's stone.Though clearing my cache and some files managed to get my store items back, so I appreciate the link!