Beyond Tomorrow (1940)

“Melton, Chadwick and O’Brien, rich but lonely heads of an engineering firm, invite two young strangers to dinner on Christmas Eve. The two, James and Jean, fall in love and become friends with their three benefactors…until the latter are killed in a plane crash and come back to their old home as ghosts. In the coming months, true love encounters some rough spots; can ghostly O’Brien help the young folks?” -imdb.com