Old Andrew’s Mount . . . the highest point in the garden . . . The western slope of the mount and the meadows to the west and north are the most recent acquisitions of the garden .. . . A gravelly pit on this western slope marks a mystery. It was hollowed out and roofed over by a solitary called Old Andrew. Here, mailed in silence, he lived for several years and no one knew his history. One day he disappeared. Weeks afterward, the body of a man past recognition was found in the vicinity. It may have been Old Andrew’s but there was no definite proof. At any rate, he was never seen again. His cave and trenches furrowing the meadow below, which he attempted to farm are the only traces of his life among us.

Shortly after Old Andrew’s cave was included in the Garden, the curator’s work was interrupted by the sound of an axe coming from that direction. Rushing up the incline to ward off the trespasser, she found no one, and heard nothing, but, when her work was resumed, the experience was repeated. This happened again and again, for two or three days in succession.

A sense of mystery the spirit daunted,
And said, as plain as whisper in the ear,
The place is haunted.
(unknown source)

Old Andrew used to cut wood for the neighbors. Could he be the ghostly woodchoppper? Means were at once taken to exorcise him. The cave was cleared of fallen tree trunks and branches. Basketfuls of violets, hepatica, wild columbine and trailing fern, with a generous amount of rich loam, were dibbled in. And thereupon the “perturbed spirit” was induced to rest.

That is the end of the Butler text, but in 1924 she provided some additional details in a newspaper interview: (pdf copy)
She was quoted “Of course, being New England born, I don’t believe in ghosts, but years ago when Glenwood Lake was known as Keegan’s Lake, an old hermit lived in a cave in the woods. Suddenly he disappeared. Three months later a body was discovered which was believed to be his, anyway, he was never seen again. ” After checking out the cave she said "At the bottom of the rubbish I found a big old boot. I buried it deep and planted violets and trillium on top. And, whatever the reason, the sound of the ax was heard no more."