Some background: the ghostly psionic character in question is a ghost due to in-campaign events which I shall skip over unless needed. Mechanically this is represented by a level of ghost racial class from the Savage Progressions web articles. Over the course of the campaign, the character has gained as additional 3 ghost levels, and took just one feat from Ghostwalk: Ectoplasm - but we are simply using the feat as is without the rest of the setting baggage. In case it matters, it is an Oerth / Greyhawk-based campaign.
The Ectoplasm feat allows the production of ectoplasm by the ghost from any part or parts of their body, in a few colors, and in sticky or slippery consistencies which give minor bonuses to certain actions. It is a ghost touch material.
Thus, how might the ghostly psionic character be able (or unable) to interact with the skin and the results of their powers when they are in a state of manifestion, and the skin, astral construct, and wall being located on the Prime Material?
Interact for this question means to hide inside, pass through/are blocked, manipulate, inhabit, or wear the skin/construct, etc.. Other examples of ectoplasm and interactions with ectoplasm that might be useful are welcome even though I did not list them in my question.
(The 3.5 tag is because most of the item/effects are 3.5, and the 3.0 tag is because Ghostwalk and Savage Progressions are 3.0.)