The shower glass can take a bit of elbow grease to clean, but even hardcore scrubbing wasn't going to remove an alarming message discovered etched into one homeowner's door.
The homeowner shared an image on Reddit of the mottled glass, claiming there to be mysterious words etched into their shower door.
"Saw this while taking a shower one day," he said. "It wasn't there before and it was on the inside of the double pane glass."
He said the words couldn't be wiped away or scrubbed off, claiming the lettering was "inside on the double pane glass".
But one social media user altered the exposure of the man's image - and it revealed some disturbing words.
"It says, 'My death is ok. Sorry it hurts you'."
Another added that making the image back and white and adjusting the exposure allowed the words to be seen clearly.
The detective work shocked the homeowner, who said the message may have been left by his best friend and cousin, who died in a motorcycle accident several years ago.
"He was a prankster. We would always mess with each other."
Other Reddit users were not so light-hearted about the spooky message.
"Oh god, that just gave me the chills," said one.
"OK, I'm scared. That's chilling," another added.