When does The Ghost & Mrs. Muir return?

The Ghost & Mrs. Muir is an American sitcom based on the 1947 film of the same name. It premiered in September 1968 on NBC. After NBC cancelled the series, it was picked up by ABC for its second season.
The series stars Hope Lange as Carolyn Muir, a young widow and writer who rents Gull Cottage, near the fictional fishing village of Schooner Bay, Maine. The cottage is haunted by the ghost of its former owner Daniel Gregg, a 19th-century sea captain, who died in 1869. The book of the same name, by R.A. Dick, was published in 1945.