I've just been watching The Man Who Haunted Himself on dvd, a film from 1970 which stars Roger Moore,who was half way between from being The Saint to being James Bond.
Briefly Roger plays Pelham,who almost dies (actually he dies but is revived) on the operating table following a traffic accident. Ignoring the lapse in logic and various plot holes, the revival of Pelham creates two of them who then lead seperate lives whilst increasingly become connected.
As the film evolves, the 'good' Pelham becomes more and more aware of the 'bad' Pelham, whom he initially thinks as either part of his imagination or the result of a prank.
Interesting if rather dated film,its worth getting the dvd to see all the old sixties cars on the streets of London.