Investigators said the 50-year-old southern Sweden woman noticed a man following her while she was walking home and she heard a noise coming from her front door a short while after she arrived at the house, The Local.se reported Wednesday.
The woman investigated the sound and discovered the man sticking his penis through her mail slot.
The man fled the scene when the woman opened the door. Police said the same man allegedly exposed himself to a woman on the street the following day.
The man has been charged with two counts of sexual assault stemming from the incidents in July. He faces minor drug charges after traces of amphetamines were found in his blood.