What’s a Ghost Going to Do? by Jane Thayer, 1966.

Gus is a friendly ghost who lives a quiet life alone in his old house, which is run-down and shabby, with winter visits from his mouse friend.  However, Gus discovers one day that the property is being sold.  The government wants the land to turn into a park, and if that happens, Gus’s house will be torn down!  If they decide to tear the house down, where will he go?

For a time, Gus tries living with another ghost in another old house nearby, but that arrangement doesn’t work because the other ghost doesn’t like Gus rattling chains.  Then, Gus tries living in a hole with his mouse friend, but it’s really too small for him.  The only place that seems right for Gus is his old house, which is in danger of being destroyed!

In desperation, Gus whispers in the ears of the man in charge of preparing the park for the government, Mr. McGovern, trying to get him to notice the virtues of his house.  Fortunately, Mr. McGovern accepts Gus’s vision of the house as a beautiful piece of the past and finds a way to restore it to its former glory so that Gus can keep his home and others can appreciate it, too.

Gus’s house becomes a museum in the park, and Mr. McGovern also officially acknowledges Gus as the resident ghost.

The book is available to borrow and read for free online through Internet Archive. It’s part of a series.