People in Derbyshire are being asked to put up posters in their windows if they do not want to be disturbed by trick or treaters around Halloween.
The posters have been sent to libraries and neighbourhood watch groups to help avoid any problems with unwanted callers, police said.
Officers have also asked that people keep safe when trick or treating.
The posters are part of Operation Relentless, a seven-week crackdown on anti-social behaviour in the county.
"For some people it can be a distressing experience having to face a stream of unexpected callers on your doorstep in the dark, wearing costumes and masks," said Insp John Coxhead.
"These visits can leave people, particularly older generations, feeling vulnerable.
"We don't want to spoil people's fun but it is vital that those who go out trick or treating do so safely."
The first phase of Operation Relentless, in May and June, saw 700 arrests and a 12% fall in burglaries.