Except that your targets) are all the ghosts in the structure, not the structure itself. The ghosts don't touch the structure. I don't think touching the structure is going to work in this case.
Checking for comparable spells, there really isn't a good example. Ordinarily, I'd agree with you-- that touching the structure would be acceptable because all of your targets would be in contact with the structure, but since the ghosts don't touch anything, I think you need voice for this effect.
-Ben.
from page 113
(the underline was mine)
I looked at pages 35 and 36 of Calebais and did not find any special notes in the section labeled "ghosts".
An (addmittedly quick) galnce at 126-128 of True Lineages (ghostly armies) also failed to turn anything up.
Mysteries revised seems to repeat only the information in Calebais.
Shiver of the departed; there doesn't seem to be a good intellego mentem guideline. I might use level 4 "sense the state of conciousness of one inteligent being" sensing the existence of a mind might be argued to be easier than this or it might be argued that an intellego vim spell of level 40 would be required. I'd use a base 4 intellego mentem for a final level of 14 but with no published guideline it is up for some debate.
Forced ambulation of the undead I might base off of the level 15 guideline "control a human being" for a final level of 51 (yuck).
So now I'm trying to figure out how to move the wimpy ward rather than moving the ghost.
Just to clarify the intent of this device.
The device is solely to trap and hold the spirits so that the creator can use other nasty spells on them. There is no need to summon the ghost into the circle, this will be done via a spell. Hence the lvl 40 one way ward is to keep ghosts IN the devices circle so that other effects may be used on them.
As for touch range on ghosts, surely sticking ones hand into a ghosts "body" would count as touch. Just because that touch has no effect due to the lack of a physical corpus doesn't mean you aren't at touch range.
I hadn't thought of a method to compel the undead through concentric rings, i'll have to think on that. However, this does again require a quite powerful spell to punch through high mahgic resistance. Which brings us back to the original dilemna.
I'm looking to use this device for interrogation, negotiation with hostile spirits and punishment for ghostly servitors.
Yea, that's a tough one to do through a device. However a spell to compell spirits do do a simple task for you would, I suspect, certainly be the sort of formulaic tool that a necromancer would want. At range voice target individual duration momentary you're only up to level 25. Could you get your 40 penetration with a level 25 spell? (including bonuses for aura, voice and gesture bonuses, virtues, and if you've got one, a talisman attunement)
You have said this twice now, and no one has questioned it, but is it in the RAW, or just an assumption on your (our) part?
The RAW are rather brief on the subject:
"Touch: The magus or anything he touches, whether a person or thing."
If a ghost surrounds you, passes through you, does it not still touch you? If it touches you, are you not touching it? Just because you can't feel it, just because a club doesn't crush it, just because it's incorporeal, doesn't mean you can't "touch" it- you don't sense the touch, there is no resistance, much as touching air, or touching a boundary to a spell, or the edge of a Regione, but the contact is there, indisputably.
With only the one line above as a citation, I would submit that Touch would be perfectly viable, and that incorporality has no effect on such a determination.
Vision of the Haunting Sprits (ArM p150) is range Touch, target Room.
you can create (new) things at Touch range - nothing to touch beforehand.
You can affect visual or scent or sound images (XxIm) at Touch Range - intangible all
You can affect lightness/darkness (Ignem) at Touch range - including eg touching a sun-beam
You can affect spells in-place with Touch Vim spells - and spells are intangible
Mentem is just another Form - like any other
ergo - you can affect Mentem things at Touch range even if intangible - you need to put your Touch (hand, whatever) up to or within the area to be affected.
(And as for Touch/Room spells you just need to be touch the room, even an outside wall - cf many example spells. Room Target then affects all within the room area; also Struct, Boundary, Circle. The contents or an area/volume Target need not be touching the area/volume/container themselves - they need to be within the Target. Range is range from Magus to Target (edge of Target))
Ghosts have some mild oddments about themselves, about not being able to affect the real world - because they are ghosts, and need to spend Might to affect real things, which is very hard for ghosts - but not eg for Elementals or Airy Spirits)