A pervert plumber got a secret key cut to a customer's home and used it to go in and masturbate over her clothing while she was at work.
Shuaib Muhammad planted a sex toy in the woman's bathroom and left women's underwear inside the house after he let himself in using a duplicate key he got cut at Asda.
Newcastle Crown Court heard the 24-year-old made silent phone calls to the customer, a professional woman in her 20s who lived alone, stole her clothing and hacked her Facebook account to find out more about her.
When Muhammad, of Marshall Wallis Road, South Shields, was arrested, police found items of women's clothing, in various styles and sizes, as well as a sex toy in his van.
It was not possible to identify where the clothing, which had been worn, was from, due to the number of addresses Muhammad visited during the course of his work.
Muhammad admitted stalking the woman, who has moved home as a result of the distress he caused her.
Prosecutor Kevin Wardlaw told the court the married dad had been hired by the woman to carry out work at her home in Newcastle last spring, and she felt at "ease" with him due to their similar ages and backgrounds.
She contacted him again last summer when a leak developed in her property.
"She had to leave for work and left him in the house with keys for the address," said Mr Wardlaw. "He attended the local Asda, obtained a duplicate key for the back door, returned to the address, and posted the keys she had left him through the letterbox.
"The defendant, at various times while in the address, used her underwear for the purposes of sexual gratification.
"He stole items of clothing. He left a sex toy in a bathroom drawer.
"He also made attempts - and did succeed - in hacking her Facebook account with a view to obtaining information, and subjected her to a number of silent telephone calls at various times of the day, 20 in total."
The victim told police she now lives in fear someone will get into her house, or is already inside, and suffers nightmares.
She said in a statement: "I cannot seem to find peace any more."
Mr Recorder Ben Nolan QC made a restraining order to keep Muhammad away from the woman for life, and said he must abide by a Sexual Harm Prevention Order for seven years.
The judge said Muhammad had become "obsessed" with the woman, and "the risk of serious sexual harm posed to young adult females remains high".
He told him that the victim was "utterly devastated by what you did to her and within her home".
Fiona Lamb, defending, said Muhammad is "embarrassed and ashamed of himself and the shame he has brought on his family", and has sought professional therapy to deal with his problems regarding sex.
Muhammad was jailed for two and a half years.