Terrified residents say they have been woken by a woman "crying through letterboxes" in the early hours of the morning - sparking fears of a bizarre robbery trick.
The residents said they were woken by the sound of someone knocking at their doors from around 4am on Sunday morning.
When they failed to answer, they said a woman then began to cry for help through the letterbox.
People living in Tranmere, Rock Ferry and Beechwood in Wirral reported similar incidents, the Liverpool Echo reports.
Residents in Kirkby reported the same of incident in July, and at the time said they feared it was a bid to steal from their homes.
One woman in Birkenhead, who asked not to be named, said: "My neighbour said she heard someone banging on her door on Sunday morning. When she looked at the clock it was about 4.30am.
"When she'd woken up a bit she said it sounded like a woman saying 'help me' and asking her to open up.
"She said she didn't know what to do but she didn't answer. It really scared her."
Similar incidents have been reported on social media, with one woman in Tranmere saying she heard a woman shouting through her letterbox at around 5am on Sunday.
Merseyside Police was asked if it was aware of residents' concerns.
In Kirkby, residents posted a series of warnings on social media over the summer – saying they firmly believed the crying woman was "part of a trick where you open the door to let the woman in and someone barges in to rob you".
One woman wrote on Facebook: "Around 2am on Friday morning we heard banging on our door but I was too scared to go down.
"I stopped my boyfriend going down because I was shaking. You just don't expect it."
Another said: "Oh my god. On Saturday morning a woman knocked at 4am and wanted the loo."
And a third woman posted: "Happened to me too, at about 4am someone was knocking at my door. I never opened it."
Following the incidents in Kirkby, officers visited concerned residents to give them advice on safety in the home.