From: MINSTRELSY OF THE SCOTTISH BORDER by Sir Walter Scott:
The Scottish Fairies, in like manner, sometimes reside in subterranean abodes in the vicinity of human habitations, or, according to the popular phrase, under the “door-stane,” or threshold; in which situation they sometimes establish an intercourse with men by borrowing and lending, and other kindly offices. In this capacity they are termed “the good neighbours,” from supplying privately the wants of their friends, and assisting them in all their transactions, while their favours are concealed. Of this the traditionary story of Sir Godfrey Macculloch forms a curious example.
As this Gallovidian gentleman was taking the air on horseback, near his own house, he was suddenly accosted by a little old man arrayed in green and mounted upon a white palfrey. After mutual salutation, the old man gave Sir Godfrey to understand that he resided under his habitation, and that he had great reason to complain of the direction of a drain, or common sewer, which emptied itself directly into his chamber of dais, Sir Godfrey Macculloch was a good deal startled at this extraordinary complaint ; but, guessing the nature of the being he had to deal with, he assured the old man, with great courtesy, that the direction of the drain should be altered ; and caused it to be done accordingly. Many years afterwards Sir Godfrey had the misfortune to kill, in a fray, a gentleman of the neighbourhood. He was apprehended, tried, and condemned, The scaffold upon which his head was to be struck off, was erected on the Castle-hill of Edinburgh; but hardly had he reached the fatal spot, when the old man, upon his white palfrey, pressed through the crowd with the rapidity of lightning. Sir Godfrey, at his command, sprung on behind him ; the “good neighbour” spurred his horse down the steep bank, and neither he nor the criminal were ever again seen.