I had some wonderful PM conversations with Freda, who used to post here. She was part of a spiritualist circle, trying to contact the dead and make a real scientific discovery to be able to demonstrate to skeptics that what they were doing was real. What impressed me about her was that she very willingly shared the experiences that led her to believe (at least in PM--she got very defensive in threads), and when I offered alternative explanations, she actually listened, and tried to be open to those possibilities.
I am convinced that she was not "deluded" so much as "ignorant"--not actively deceived, so much as not having all the information. The explanation she had for her experiences fit, but she was not opposed to hearing a more mundane explanation. She thought that she was doing important work on an important topic; I do not think she was trying to trick anybody.
Was what she claimed, the truth? No. If the adjective "ignorant" was not available, "deluded" would come close. (And in truth, if I only had access to her public posts, "deluded" would come even closer.)