Horror novel advertised at the end of a ghost story novel

Question

I'm looking for a book that was advertised at the end of a horror/drama novel about a haunted house. I'd accept either the name of the primary book or the book that was being advertised. I read it in the early 2000's from my grandparents' collection, so it's probably a fair bit older than that. It was a standard 150 - 200 page sized paperback book.

The advertisement was just a single early chapter clipped and printed at the end of the main book. A man and a woman arrive tired at a secluded cabin after struggling through the elements (snow, I think). They talk about fooling around, one of them objecting to it because someone might look through the window and the other one joking that if anybody followed them they deserved a show. They light the fireplace and start to have sex, the woman falls asleep midway through before anything R-rated happens, and she wakes up in distress. I remember less about what happens next, but I think it involved her running outside and seeing an older woman being admonished by another entity that something had gone wrong and some bad force was breaking out or something to that effect. It had a nightmare-ish quality and the woman didn't know anything about what was happening and I think she died at the end of it.

The book it was attached to was a memoir of a family that moves into a house and are haunted by the previous owners. It was written from the husband's point of view. It wasn't scary and the book was handled as a true story with a twinge of romance. One of the subplots in the book was the husband inviting his friend over to investigate why the house measured bigger on the outside than the inside, and after investigating they found a hidden room with a newspaper with a recent date, and that mystery being unresolved by the end of it but related to the haunting. I think in the afterward there was section where the writer of the book was convinced to write the book by a recently deceased relative.

Answer 1

I figured it out by asking some members of my family, the book was Night Stalks The Mansion by Constance Westbie and Harold W. Cameron.

The book has the section I remember with the newspaper in a hidden room on page 127:

Minutes later we both climbed down into our secret room. Careful examination proved that there were no other windows and no other way of getting into the room. If there had been a door, it was certainly sealed over with concrete. The entire room was cement lined. A patchwork quilt was on the floor in the comer. It was dirty and stained. There was also an old newspaper near it that I picked up, folded and put into my pocket. By working in teams, we found that hitting against the ceiling with a broom handle would give an answering vibration on the kitchen floor above.

And then later on 129, the date being addressed:

They gathered around me as I spread it out, upsetting half a cup of coffee that Dorothy quickly sponged up. What I saw as I read that paper rocked me back on my heels — and I have never fully recovered. I couldn't speak. I could only point to the date. The newspaper was only six months old.

As for the advertised book, it was The Guardian by Jeffrey Konvitz. The bits advertised start on the November 1978 section. The softcore erotica is what it is and was accurate, and the section with the old lady being admonished starts shortly after:

She ran into a small gully and squinted in the direction of the light. Yes, she could see it, no more than a hundred feet away. She pushed forward, aware of the men walking calmly close behind, delighting in her agony.

Brushing aside some branches, she entered a clearing. Standing across from her was a figure in a nun's habit, surrounded by a strange aura of light. The nun's eyes, bulging and swollen, were covered by hideous white cataracts. Her skin was wrinkled and cracked like dried clay, her lips blue and thin. Her hair was dead, stringy and broken, laid over a waxen complexion. She was breathing slowly. Her hands clutched a gold crucifix.

...

The old man pointed. "I name thee damned, Sister Therese," he said. "And your rejoicing should be considered. Your penance is nearly served." He stepped closer. "Then shall the minions of Hell o'erstep these bounds. I, Charles Chazen, declare the moment at hand!"

You can read the referenced bit on Google Books here.