Perhaps infrasound, described in Vic Tandy’s A Ghost in the Machine Here’s a brief of it: https://higgs.ph.ed.ac.uk/outreach/higgshalloween-2021/haunted-freque

Perhaps infrasound, described in Vic Tandy’s A Ghost in the Machine Here’s a brief of it: https://higgs.ph.ed.ac.uk/outreach/higgshalloween-2021/haunted-frequency https://higgs.ph.ed.ac.uk/outreach/higgshalloween-2021/haunt... The full story is a PDF that is the first google result of “Vic Tandy’s Ghost in the Machine” e.g. failing mechanical equipment