A few months after his capture and death, John Wilkes Booth was sited in McVicker's Theatre, the Madison St. theatre where he had performed a couple of stints in Chicago. No one said it was a ghost, though - they simply said that it was evidence that he hadn't really died at all. Conspiracy theories of this nature are still going around; for years, a mummified version of the REAL Booth was a big hit at carnivals.
In 1866, a seance to contact Booth's spirit was held in a house on the West side. His ghost came when called (or, anyway, the medium made it SEEM as though he did - these things were pretty generally bogus) and his voice was heard, but he did not appear visually, since "the devil would not permit it."
In any case, the "ghost" gave a whole new version of the assassination story, stating that he fired at Lincoln from the front, but that the President turned his head, which is why the bullet entered from the back. He also stated that he broke his leg not in the jump to the stage but by falling from his horse later (this, in fact, happens to be correct).
He went on to say that he had also planned to kill Vice President Johnson (which, in fact, was someone else's job). He was most emphatically glad that he had killed Lincoln, but equally glad that he hadn't killed Johnson, who he liked very much (which makes sense, since Johnson was probably the most racist president ever; Booth's ghost was sure he would re-establish slavery). He wouldn't support his re-election, though - he argued for McClellan (a Union general who spent most of the early days of the war sitting on his butt, then ran against Lincoln in 1864) or Robert E. Lee as the next President and even mused about a McClellan / Lee "dream ticket."
He was then asked:
Q: "Are you in heaven?"
Q: Are you in the other place?
Q: Is there a devil there?
Q: Does he treat you rough?
A: YES! (the tabble jiggered violently here).
Q: Do you think you deserve it?
He went on to admit that he was a pretty bad actor (he was fairly eccentric in his portrayals of well known Shakespeare rolls, but the Trib called him a genius), but was just as good as his brother, Edwin (who was widely thought of as the greatest Shakespearean actor of the day), and went on at great length about President Johnson and the type of people who supported him in the form of "automatic writing" before disappearing abruptly.
Seances like these - with knocks on tables, etc - were all the rage around the time of the Civil War. Mediums found all sorts of fascinating ways to fake them, up to and including pulling cheese cloth out of their more nefarious orifices and calling them "ectoplasm." Even the most die-hard believers knew that most of the "mediums" were frauds.