The history of alien abduction in Scotland
In Scotland the modern abduction and changeling story of Robert France was noted by Brian MacMullen where the image of Robert France was seen to wink out and a small grey being left standing in his place.
The following article shows that what is going on today has been going on for a long time.
Here from the
The Folk-Lore of the North-East of Scotland By Walter Gregor 
Sometimes they succeeded in carrying off an unbaptised infant, and for it they left one of their own. The one left by them soon began to "dwine," and to fret and cry night and day. At times the child has been saved from them as they were carrying it through the dog-hole.
A fisherwoman had a fine thriving baby. One day what looked like a beggar woman entered the house. She went to the cradle in which the baby was lying, and handled it under pretence of admiring it. From that day the child did nothing but fret and cry and waste away. This had gone on for some months, when one day a beggar man entered asking alms. As he was getting his alms his eye lighted upon the infant in the cradle. After looking on it for some time he said, "That's nae a bairn; that's an image; the bairn's been stoun." He immediately set to work to bring back the child. He heaped up a large fire on the hearth, and ordered a black hen to be brought to him. When the fire was blazing at its full strength, he took the hen and held her over the fire as near it as possible, so as not to kill her. The bird struggled for a little, then escaped from the man's grasp, and flew out by the "lum." The child was restored, and throve every day afterwards.
Another. A strong healthy boy in the parish of Tyrie began to "dwine." The real baby had been stolen. A wise woman gave the means of bringing him back. His clothes were to be taken to a south-running well, washed, laid out to dry beside the well, and most carefully watched. This was done for some time, but no one came to take them away. The next thing to be done was to take the child himself and lay him between two furrows in a cornfield. This was carried out, and the child throve daily afterwards. All this was annoying to the "fair folk," and rather than submit to such annoyance they restored the child, and took back their own one.