In The Scarlet Letter, what is 'Old Manse' and what is its relationship to the Custom House? are they the same thing or...?

"The
Custom House" is an autobiographical addendum thatincluded as the introduction toThe
Scarlet Letterafter he felt that the novel itself was a bit too short for publication. It also
serves as a wonderful foundation that gives a nostalgicto the re-telling of the story of , and
her vicissitudes.

In "The Custom House", Hawthorne also explains
the rationale behind writing about his experience in the Salem Custom House is because he had
already published a story of a very similar style about his experience at an Old
Manse.

to which Hawthorne refers is a historically-famous dwelling located
in Concord, Massachusetts, which was built in the 1770's by Ralph Waldo Emerson's grandfather,
the Reverend William Emerson.

This place held a lot of sentimental value to
Hawthorne because he lived there with his new bride Sophia Peabody for around three years. Those
seem to have been particularly happy times for the couple, motivating him to publish in 1846 a
collection of short stories titledMosses from an Old Manse.

Hence, to
specifically address your inquiry, The Old Manse and the Custom House are completely different
places; they are places to which Hawthorne had lived and worked at respectively, and he mentions
them both in the autobiographical introduction ofThe Scarlet Letterjust as a clever stylistic
device.