Ominous warning behind bizarre sign left on the door of an ordinary house

A homeowner has been warned their home could become a target for thieves after an X-shaped sign was mysteriously left on their front door.

The mysterious symbol, made from a few leaves, was taped to the fly screen door of the home on Slacks Creek, south Brisbane, on Saturday.

Alex Munroe, who lives in the house, said he went outside in the morning and found the X sign when he returned a short time later.

He took a photo of the sign and uploaded the image to Reddit asking others if they knew what it meant.

“Someone left an X made of leaves on our front door,” he wrote.

“Neighbors didn’t see anything, and it’s probably just some kids messing around, but they wanted to ask if anyone else has come across something similar or heard of an incident like this.

‘I wonder what we should plan.

The post was flooded with hundreds of comments from social media users, who suggested someone could have created the symbol to check if anyone lives in the property.

“I’d say it’s a burglar, but not in the way people think,” one person wrote.

‘They mark a house to see if you take it away. If it’s not removed, they’ll know the residents are gone.”

Others said that in many European and Mediterranean cultures, the sign is often used when someone is visiting a friend but the house is empty.

“My grandparents do something similar to let their friends know they visited when no one was home,” one person wrote.

Locals made the mysterious discovery on Saturday after he returned to his home in Slacks Creek (pictured), south of Brisbane.

“Old neighborhood with Italians, Greeks or something like that?” asked another.

“This was an old way of saying you were coming over to your house.”

Some said it could just be a harmless joke and saw the funnier side by suggesting it could be an invitation to participate in a game.

‘The beginning of a tic-tac-toe game. Put a 0 under it,” someone wrote.