The script itself isn't too difficult, and can be keyed to onactivate, onpcdrop, onpcequip, and so forth. the cursed items that summon the dremora and dwemer ghosts and so forth use the basic script.
As to dialogue, when you make the creature, set the ai fight to 30, flee to 10, alarm to 30, hello to 30. Then if you want it to attack, startcombat in the dialogue results box.
Begin BILL_MarksDwvGhostSummon; Summon an Dwarven Ghost when a cursed Dwarven coin is pulled from a skull;; script location: should be placed on a Dwarven Coin stuck in a skull;fixed 03/20. Could still be wierdness.; variablesshort doneif ( OnActivate == 1 ) if ( done == 1 ) Activate return else PlaceAtPC "dwarven ghost", 1, 128, 1 ; 1 of them, 256 units away, in back (1) of the player set done to 1 Activate endifendifEnd
This is probably the code you had or very similar. All you have to do is change the object ID from dwarven ghost to the object ID of whatever creature you want summoned. Just remember that if you want dialgue, it has to be a creature whose AI fight isn't still 90.