How Demi feels about herself seems to depend on the day of the week. She can be by turns a sultry hoyden, a cool commandant or a grungy pixie. But at home in Malibu, under the celebrity hair affairs and the high-concept makeup, her vulnerable brown eyes (that may leak tears at any moment), shimmering auburn hair and mouth (pursed to deliver a joking taunt) make her a tantalizing partner. Admitted hubby Bruce Willis: "The girl you saw in Ghost ïs what I fell in love with." He's not the only one. In Proposal, Robert Redford offers a ravishing Demi a million-dollar rental fee to spend the night. Would Mrs. Bruce Willis ever consider such a deal? Not a ghost of a chance.