Police say a Carterton resident was woken about 1:30am on Saturday by knocking at their door, then confronted in their own hallway by four people who had come into the house.
One had a long-barrelled firearm, likely to be a shotgun or rifle, and another was brandishing a hammer.
Detective Snr Sgt Barry Bysouth said it was a targeted attack aimed at stealing cash and electrical items.
He said they searched the house and stole some items then left in a vehicle, possibly toward Lincoln Rd.
"The homeowner has experienced a terrifying ordeal, and while not physically harmed, has been left extremely shaken."
Police said the intruders were wearing dark clothing and bandanas on their faces; one is described as stocky and tall, another tall and slim and the third as small and thin.
Police do not believe there is any risk to the wider community at this time.
They want to hear from anyone who saw a vehicle in Frederick St between 1:30am and 2am on Saturday.