The Hudsucker Proxy movie

When Waring Hudsucker, head of hugely successful Hudsucker Industries, commits suicide, his board of directors, led by Sidney Mussberger, comes up with a brilliant plan to make a lot of money: appoint a moron to run the company. When the stock falls low enough, Sidney and friends can buy it up for pennies on the dollar, take over the company, and restore its fortunes. They choose idealistic Norville Barnes, who just started in the mail room. Norville is whacky enough to drive any company to ruin, but soon, tough reporter Amy Archer smells a rat and begins an undercover investigation of Hudsucker Industries.