Mysterious Knocking Sound from inside my house last night

[Herbert The Love Bug]

the only knocks I hear in my house are from the demon that attacked me and came home with me. He's pretty fuging crazy

[Kevin Greene]

Sorry it was me, got piss drunk at the bar around the corner and brought home some floozie to your house by mistake. It was the head board in the guest room banging on the wall.

Heads up, you might want to change the sheets before you have company spend the night.

[C47]

Last time I went up into the attic after wifey heard a strange sound at 2:30 in the morning I nearly got attacked by a Raccoon. Good luck!

[jtnc]

Rats.

[YoungPanthers89]

Hash slinging slasher

[Niner National]

2. If the HVAC returns are blocked, the dampers will flutter and echo through the duct work, but this occurs when the AC shuts off.

Had this happen to me recently, except mine was due to me having too many vents closed (the heat is unbearable on the third floor). With most of the vents upstairs closed, too much air was backing up in the duct work making it bow outward. When the heat shut off, they went back to their normal size making a loud banging noise.

Took me a while to figure out what it was. Was afraid my HVAC unit was about to break and I was pissed because I've only lived in the house for a year.

[PhillyB]

probably something terrifying

[TNPanther]

[Bronn]

Muggsy Bogues

[Cary Kollins]

Hurney was wasted again and forgot which house was his.

[Hawk]

whatever it was must have got him...he hasn't been back

[chknwing]

my guess is squirrel/racoon or something stuck in the wall or walking inside you ductwork. I get cats under the house all the time that get up in the ductwork.

[Captain Morgan]

MKG