In "The Devil and Tom Walker," why does Walker tell his wife about his encounter with the Devil?

Let us remember what happens when Tom first reaches home
after his encounter with the devil. Having just sat next to a rotten stump bearing the
name of Absalom Crowninshield, he comes home to be greeted by the news that the same
person, infamous for his bucaneering, has just died suddenly. This serves to make Tom
feel that all that had occurred to him was not a daydream but was actually real and
true. The story itself thus explains why Tom feels inclined to take his wife into his
confidence:

He
was not prone to let his wife into his confidence; but as this was an uneasy secret, he
willingly shared it with
her.

Thus we can see that the
nature of this "uneasy secret" meant that Tom overcame his normal suspicion of his wife
and felt he had to confide in someone and tell them what he had
experienced.