Gunshots were fired in a "targeted attack" in the Grange area of Preston, police said.
A 33 year old man was arrested on Monday under suspicion of possession of firearms with intent, and remains in police custody.
Detectives are still investigating what they called a "targeted attack" at 9:10pm on Sunday, when two rounds from a shotgun were fired at the front door of a building on Sulby Grove, near the Preston Bypass.
No one was injured in the attack, and officers have now appealed to the public for information and witnesses.
Det Insp Fiona Jackson, of Preston CID, said: “We have launched an investigation following this incident and are appealing to anybody who saw or heard anything suspicious, or who has any other information that could help with our enquiries, to get in touch as soon as possible.
“It is incredibly lucky nobody was hurt and our enquiries are very much on-going.
“While we have made an arrest we would encourage anyone who can assist our enquiries to come forward. We are particularly keen to trace any witnesses, or anyone with dashboard mounted camera footage which may have been recording in the area around the time of the offence.
“At this time we believe this was a targeted attack and there is no wider threat to the public. However we know this will have been concerning for residents and we have stepped up patrols in the area, which we hope will offer some reassurance to local people.”
Anybody with information can call 101 or email email@example.com quoting log number 1667 of August 11.