Two maintenance workers who were the first to enter the Pennsylvania home where a mom and her teen daughter allegedly murdered five relatives described to The Post on Wednesday stumbling into the house of horrors — and not initially grasping the toll amid their sheer shock.

Bud Millor and Ray Hamber opened up the door of Shana Decree’s apartment in Morrisville — about 30 miles north of Philadelphia — on Monday afternoon for a caseworker from Bucks County Children and Youth, who was concerned that they hadn’t been able to reach the family for days.

“I just saw two bodies laying in bed covered up,” Millor, 63, recalled of the moment they pushed into the ransacked apartment. “I saw they were barely breathing.”

Millor was so stunned by the sight of Decree, 45, and her 19-year-old daughter, Dominique, clinging to life that he said he didn’t even notice the five dead bodies strewn around the same bedroom.

“I didn’t see no bodies. I didn’t see no death,” said Millor. “All I saw was two women barely breathing, and that’s when I backed off” and called 911.

It was responding cops who found the five bodies, identified as two of Shana’s children, Naa’Irah Smith, 25, and Damon Decree Jr., 13; Shana’s sister Jamilla Campbell, 42; and Jamilla’s twin 9-year-old daughters, Imani and Erika Allen.

Police believe the murders happened sometime between Saturday and early Monday, but Hamber had reason to believe they were committed on the recent end of the range.

“I didn’t smell death until yesterday,” said Hamber, 68.

It wasn’t immediately clear what caused Shana and Dominique’s apparent medical distress, but investigators at the hospital noted Dominique had visible injuries to her neck — and her mom said that the family “wanted to die” as part of an apparent murder-suicide pact, officials said.

Both women have been charged with five counts of homicide and one count of conspiracy.

A family friend previously told The Post that a relative tried to check in on the clan in recent weeks, only to find them ranting about the end of the world and calling her a “demon.”

Shana’s estranged ex-husband, who lives in North Carolina, told ABC affiliate WTVD she had recently fallen under the sway of an online “cult.”

The apartment complex maintenance workers said Shana and her kids had lived there for about three years, and that nothing seemed amiss until Campbell and her side of the family moved in recently.

“Things started to get fishy about two months ago when the other people moved in,” said Millor, though he declined to elaborate.

Added Hamber, “The last month or so, something changed, but we don’t know what.”

“They were nice people. They were religious,” he said. “The children were super polite, ‘Yes ma’am, no ma’am.’ ”

“You just never know what’s going on behind closed doors, though.”