You may or may not be able to see the bluish hue above and to the left of the gravestone, but it is supposed to be pictorial evidence of a ghost. I really think its there, but if you don't that is OK. As far as the Bible goes, it makes mention of one in the book of first Samuel and in the World English Bible, calls them "familiar spirits".
1 Samuel 28:7-19 WEB (R)
(7) Then said Saul to his servants, Seek me a woman who has a familiar spirit, that I may go to her, and inquire of her. His servants said to him, Behold, there is a woman who has a familiar spirit at Endor.
(8) Saul disguised himself, and put on other clothing, and went, he and two men with him, and they came to the woman by night: and he said, Please divine to me by the familiar spirit, and bring me up whoever I shall name to you.
(9) The woman said to him, Behold, you know what Saul has done, how he has cut off those who have familiar spirits, and the wizards, out of the land: why then do you lay a snare for my life, to cause me to die?
(10) Saul swore to her by Yahweh, saying, As Yahweh lives, there shall no punishment happen to you for this thing.
(11) Then said the woman, Whom shall I bring up to you? He said, Bring me up Samuel.
(12) When the woman saw Samuel, she cried with a loud voice; and the woman spoke to Saul, saying, Why have you deceived me? for you are Saul.
(13) The king said to her, Don't be afraid: for what do you see? The woman said to Saul, I see a god coming up out of the earth.
(14) He said to her, What form is he of? She said, An old man comes up; and he is covered with a robe. Saul perceived that it was Samuel, and he bowed with his face to the ground, and did obeisance.
(15) Samuel said to Saul, Why have you disquieted me, to bring me up? Saul answered, I am sore distressed; for the Philistines make war against me, and God is departed from me, and answers me no more, neither by prophets, nor by dreams: therefore I have called you, that you may make known to me what I shall do.
(16) Samuel said, Why then do you ask of me, seeing Yahweh has departed from you, and has become your adversary?
(17) Yahweh has done to you as he spoke by me: and Yahweh has torn the kingdom out of your hand, and given it to your neighbor, even to David.
(18) Because you didn't obey the voice of Yahweh, and didn't execute his fierce wrath on Amalek, therefore Yahweh has done this thing to you this day.
(19) Moreover Yahweh will deliver Israel also with you into the hand of the Philistines; and tomorrow you and your sons will be with me: Yahweh will deliver the army of Israel also into the hand of the Philistines.
Saul had disobeyed God and therefore God left him. He was alone and sought a witch to conjure up Samuel for some "spiritual" guidance. Samuel told Saul he was about to die and die he did a day later. Are spirits real? You bet they ARE! In the words of a famous character from the "Wizard of OZ": "I do believe in spooks". Not everything in this world or the next is easy to understand, but take a look at the picture once again and see if you don't see something this time. Spooky picture, isn't it?