If the Bible is correct, it was Samuel.
His answer to Saul seems to support this conclusion even if we discount the Bible's claim this was Samuel.
But we live in a more "enlightened" age where Christians prefer their supernatural a bit more subdued if it falls outside of their theological preferences.
Again, witchcraft and necromancy are abominations. Convince me from Scripture that God would speak through them when the hallowed channels are closed.
No one has power to commune with the dead That's the point. Necromancy and witchcraft are really communion with demons which are imposters, deceivers and liars.
Her own words reveal why she cried out. She was terrified when it was revealed that her client was Saul.
'Samuel's" own words reveal that he was a demon. Is a mission from God properly called a 'disturbance'? And would he appear as an old man? (the degradation of the body through old age being a result of the curse and sin)? Again, no one has the power to commune with the souls of the dead, which are in prison; and much less can they disturb the souls of the elect, who are in the Bosom of Abraham, and much more less can the souls of the elect be disturbed through the power of the Devil.
So the text says 'Samuel,' but the text also says that God would not answer Saul through the prophets. So you have no recourse through a strictly literal reading to reconcile the texts. You must say either that when the text says God would not speak to Saul through the prophets, that the author meant only the living prophets, but that an audience with dead prophets through the abomination of witchcraft would be honored; or you can say that the author meant 'Samuel' as the name the demon took to deceive Saul.
The former is absurd, and the latter is at harmony with the whole of the Scriptures.
Also she did not summon the spirit of Samuel, she had a familiar spirit. She summoned Samuel and I find it interesting that he was summoned up rather than down.
the Bible says that each human being has three distinct "parts", "body, soul and spirit"
Thessalonians 5:23, “And the God of peace Himself sanctify you wholly, and may your spirit and soul and body be preserved complete, without blame, at the coming of our Lord Jesus Christ.”
The "body" is the shell that we live in. The "spirit" is our life from God. The "soul" is the , "the moral and emotional nature of human beings".
ψυχή, "of the moral and intellectual self, of the emotional self, the conscious self or personality as centre of emotions, desires, and affections" (Liddell & Scott, Greek lexicon)
Rev 20:4, "And I saw thrones, and they sat on them, and judgment was committed to them. Then I saw the souls of those who had been beheaded for their witness to Jesus and for the word of God, who had not worshiped the beast or his image, and had not received his mark on their foreheads or on their hands. And they lived and reigned with Christ for a thousand years."
Rev 20:4,5 And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years. But the rest of the dead lived not again until the thousand years were finished. This is the first resurrection.
Rev 5:10 And hast made us unto our God kings and priests: and we shall reign on the earth.
Acts 2:31 “he, foreseeing this, spoke concerning the resurrection of the Christ, that His soulwas not left in Hades, nor did His flesh see corruption. --- Christ soul was not left, the soul David was both dead and buried, in Hades V 29
Consider: 1 Thes 4:14 for if we believe that Jesus died and rose again, (from Hades Acts 2:31)
so also ( From Hades, by resurrection) God those asleep through Jesus he will bring with him, (To rule with him on the earth Rev 20:4,5 Rev 5:10)
As a person who's read eleven different Bible versions cover-to-cover repeatedly, I've never seen one quark of Scripture saying it eas anyone or anything but Sam who appeared.
And Sam was a bit miffed, as he said to Saul, "Why have you disturbed me?"
There's simply no good reason to believe it was anyone else!
(The witch likely surmised it was Saul, as Saul was about 7 feet tall, the tallest man in Israel. Scripture doesn't say Sammy told her.)
Consider that the Lord did indeed appear unto Balaam the first couple of times as he used enchantments:
Num 24:1
And when Balaam saw that it pleased the LORD to bless Israel, he went not, as at other times, to seek for enchantments, but he set his face toward the wilderness.