Wuchak
More silly 60's beach amusement from AIP, this time in a spooky mansion
A recently dead wealthy man (Boris Karloff) is visited in his crypt by a ghost girlfriend from decades prior (Susan Hart). To have his youth restored (as a ghost), he has to perform a good deed and so tries to ensure that someone worthy gets his inheritance hidden somewhere in his creepy manor.
The Ghost in the Invisible Bikini (1966) is the tenth beach party film by American International Pictures that released a whopping twelve such movies in less than four years from 1963-1967. I've only seen two others, "Beach Blanket Bingo" (1965) and "Dr. Goldfoot and the Bikini Machine" (1965), the latter featuring Vincent Price.
Like Beach Blanket Bingo, this one ...