Intrepid ghost-busters felt the fear while visiting historic Dalton Mills after dark.
Some participants became emotional as they toured deserted parts of the Keighley mill complex during its first Fright Night on Friday.
A total of 30 people took part in the spooky session arranged by the recently-established Fright Nights West Yorkshire.
They used scientific ghost-hunting to check for any presence, then walked around the mill in the dark with Northamp-ton medium Dan McDonald.
Fright Nights West Yorkshire is run by Kellie Etherington and Nathan Wallbank, who both have many years’ experience as paranormal investigators.
Kellie said the Dalton Lane ghost hunt, the company’s first-ever event, was a great success with all 30 tickets sold.
She said: “We had a good range of people aged from 18 to 45, including some who travelled from Scotland. There were people who were open-minded, sceptics and believers.
“We had some really good paranormal activity.
“When we were walking round some people got really emotional.
“Some of them were really sensitive to what they were experiencing. A couple felt the atmosphere change, when it got really oppressive and heavy.”
A second Fright Night will be held at Dalton Mills on June 7. Visit frightnightswy.co.uk to book a place.