When writing this "found poem" for Charlotte Perkins Gilman's "The Yellow Wallpaper," the reader will notice that there is a pattern, not just to the disturbing wallpaper, but also to the arrangement of words and sentences on the pages. For instance, many of the sentences begin with I while many others begin with He said. Also, the thoughts of the unnamed narrator are fragmented, simple, and short.
With this in mind, then, as a characteristic pattern, the reader can then arrange the "found poem" in the same manner. Perhaps, even a style imitative of Poe's in which imagery takes the place of his sound effects in the stanza with a last line that is of the same meter each time and rhyme might work. For instance, the reader of Perkins's story could compose one stanza like this:
I must not think about this paper that knows what a vicious influence it has!
I never saw so much expression in an inanimate thing before though all have such looks
I never saw a thing that was not arranged on any laws of radiation or alternation, or repeition, or symmetry
It is repeated, of course, by the breadths, but bloated curves and flourishes with delirium tremens go waddling up
I don't know why I write this. I don't want to. I don't feel able. But the effort is getting to be greater than the relief.
The next stanza can build on the narrator's fixation with the wallpaper, and then repeat the lines of the last group above: "I don't know why I write this. I don't want to......Then, in the last stanza, the reader can write as the final lines,
I suppose I shall have to get back behind the pattern when it comes night
It is so pleasant to be out in this great room and creep around as I please! But the effort is getting to be better than the relief; yes, better than the relief.
(This is a great assignment, providing you with such opportunities to write lines suggestive of the errant mind of the narrator. Take a look at Poe's poem and read a little about him to springboard some ideas.)