The secret 'witch marks' or ritual magic objects concealed within your home to ward off evil will have lain in your house undiscovered for decades.
Deliberately concealed under floorboards, in roofs, fireplace chimneys and in the voids of houses, they were placed there by ordinary people gripped by a terror of invisible evil lurking in their homes.
Now a new video from the Tasmanian Magic project has been released to help homeowners around Australia discover the secret marks.
Some of the marks look just like candle burns or scratches, or they may be more elaborate hexafoils which look like circular daisy chains.
All the houses hiding these marks will have been built before 1935 and what they contain was part of a terrible secret held by early Australian settlers.
When death and destruction came into people's lives, they blamed it on unseen evil spirits and witches which crossed over from the underworld.
Now in the hidden recesses of old houses, the marks and objects like boots and shoes, children's toys, clothing and even mummified cats are being uncovered.
Newcastle University historian Ian Evans, who started the Tasmania Magic Project, wants to uncover more.
Dr Evans hopes a video raising awareness of the existence of these marks in old houses and buildings will help to uncover the lost and secret history of magic in 19th century Australia.
The Tasmania Magic project was so named because the state has an abundance of old houses with ritual magic marks and objects.
Dr Evans had started his discovery of ritual magic practices, which he believes began in the UK and Europe in medieval times, with a child's ankle boot shoe and a woman's lace collar.
The objects were hidden behind a wall of an 1830s house in Dawes Point, one of the oldest parts of Sydney on the harbour foreshores.
Knowing that the practice of secreting ritual magic objects was linked to personal tragedy, Dr Evans investigated.
The objects dated from before 1850, when "belief in magic and the supernatural was still rife".
Dr Evans found that between 1863 and 1871 the house's occupants were a drapery store owner and city councillor, George Hurley and his wife Mary.
The couple had nine children, but the eldest George died aged 18 months after an illness of "just a few hours".
Twelve months later, the Hurleys' second son died aged three months, and their next child, a daughter Louisa, died from convulsions aged 21 months.
Dr Evans' second discovery was a tradesman's boot in a chimney breast of a country house in the NSW town of Mudgee.
Builders or tradesman would conceal objects during construction to ward off spirits for the new owners.
Soon he was finding mummified cats, children's toys, hexafoils and other anti-witch symbols known as merels, and ritually burnt marks hidden on and in the walls of homes and other buildings around Australia.
Shoes were favoured because they retain their human shape after being taken off.
Cats were left to trap or decoy an incoming witch and for "the fact they protect buildings from vermin".
The objects had been turning up in houses in Europe, the UK and the US for centuries, but Dr Evans was excited to find that Australian houses seemed to hold similar secrets.
His suspicions were confirmed when he was called to a house in the Tasmanian Midlands.
Allen and Linda Cooper had bought an isolated 19th century farmhouse with an attic space where they found a single shoe.
Thinking a rat or possum may have dragged the object in, the Coopers decided to nevertheless keep on looking.
What they found sent shivers down their spines, and subsequently down Dr Evans' when he visited the house at Woodbury, 100km north of Hobart.
Hidden in the wall of a children's bedroom, in the roof and a disused bread oven, they found 38 shoes, toys, hats and dolls' clothes, all from the 19th Century, and the mummified body of a dead cat.
Dr Evans began researching the house's former occupants and concluded, "they were absolutely terrified".
An English free settler named Robert Harrison and his wife Eliza and five children had occupied the house since the 1820s.
In 1829, Mr Harrison's three-year-old grandson died in mysterious circumstances after disappearing in a possible abduction.
In 1860, four members of the Harrison family died within a month.
Dr Evans has since found concealed objects and marks in other Tasmanian houses, and around the country.
At a house in Stockton, near Newcastle in the NSW Hunter Region, Dr Evans found a woman's shoe hidden on the smoke-shelf of the fireplace.
The house had been owned in the early 1900s by Stockton Municipal Council clerk Harry Ackerman Graham, who lived there with his wife and four children.
"For convicts or settlers coming to Australia in the 19th century it must have seemed a very frightening place," he said.
"They were doing the equivalent of going to the other side of the moon and they needed comfort against a foreign world from which they knew they would never be returning home."
In Sydney's Hyde Park Barracks, which housed hundreds of convicts fresh off ships after a long and often terrifying journey from England, shoes, rosary beads and many items of clothing have been found stuffed in the walls.
"Convicts were torn from their homes and families and transported to an alien and exotic world," Dr Evans said.
"So they used folk magic to comfort themselves. Ritual concealment of these objects gave emigrants and exiles a sense of control at a time when their grip on the world seemed fragile.
"Stress, danger and death were elements contributing to the use of folk magic in the houses and buildings of Australians in the period between 1788 and 1935."
Dr Evans wants to encourage people who watch the video to get in touch if they have seen any magic marks, or find any objects.