Kama Rupa (Sans.) Metaphysically and in our esoteric philosophy it is the subjective form created through the mental and physical desires and thoughts in connection with things of matter, by all sentient beings: a form which survives the death of its body. After that death, three of the seven "principles" — or, let us say, planes of the senses and consciousness on which the human instincts and ideation act in turn — viz., the body, its astral prototype and physical vitality, being of no further use, remain on earth; the three higher principles, grouped into one, merge into a state of Devachan (q. v.), in which state the Higher Ego will remain until the hour for a new reincarnation arrives, and the eidolon of the ex-personality is left alone in its new abode. Here the pale copy of the man that was, vegetates for a period of time, the duration of which is variable according to the element of materiality which is left in it, and which is determined by the past life of the defunct. Bereft as it is of its higher mind, spirit and physical senses, if left alone to its own senseless devices, it will gradually fade out and disintegrate. But if forcibly drawn back into the terrestrial sphere, whether by the passionate desires and appeals of the surviving friends or by regular necromantic practices — one of the most pernicious of which is mediumship — the "spook" may prevail for a period greatly exceeding the span of the natural life of its body. Once the Kama Rupa has learnt the way back to living human bodies, it becomes a vampire feeding on the vitality of those who are so anxious for its company. In India these Eidolons are called Pisachas, — and are much dreaded.
Source: H.P.Blavatsky - The Key to Theosophy, The theosophical glossary