Two gunshots were fired at the front door of the property in Hyde last night.
A woman in her 30s received a minor injury to her leg that did not require medical attention.
A scene remains in place at the property on Marler Road.
Officers are currently treating the incident as isolated and there is not believed to be any threat to the wider community.
Detective Inspector Joseph Harrop of GMP’s Tameside District said: “We understand the concern that an incident like this will cause in the vicinity.
“Thankfully, this incident only resulted in minor injuries, but the consequences could have been far more severe.
“I want to reassure people who live locally that this is being treated as an isolated incident and we have a team of officers working to establish the events before and after the shots were fired.
“If you have any information that can assist us, please don’t hesitate to get in touch.”