A boy in West Molesey awoke to find a man standing at his bedroom window in the middle of the night.
The man was seen at the ground floor bedroom window at an address in Down Street between 11.20pm and 11.30pm on Friday, May 30.
The boy’s screams alerted his mother, who called the police.
It is believed the man, who was on foot, may have gone down a walkway off Down Street towards High Street.
PC Tobie Clapcott, said: "The intentions of the man are not clear and I would appeal to anyone who witnessed the incident or any members of the public who saw anyone acting suspiciously in the area at around the time of the incident to contact police - any information could prove vital to the investigation.
"There have previously been a number of reports of a similar kind in the area and I would urge local residents to remain vigilant and ensure that your property is secure; especially during warmer weather when it is tempting to leave windows open overnight."
The Elmbridge neighbourhood team is conducting house to house enquiries along with issuing advice and guidance to residents.
Anyone with information should call Surrey Police on 101, quoting reference 45140044277 or Crimestoppers on 0800 555 111.