All secrets for achievements: Keep it Secret, Keep it Safe and Finders Keepers.
Click on the bucket under the window to knock over.
Bottom left of the radio, there is a red light. Right next to it is a button. Click it and it will open the secret.
Left to the compartment is a button. Click it and it will open the secret.
Just click on the container and it will open the secret.
Hold click on the lid and push it up.
Behind the upper left pic. Tilt it to the right.
Hold click on the floor wooden piece and put it into the oven.
Hold click on the bottom left lever and move your mouse to open the secret.
Take the fiddlestick and play the violin until the secret falls down.
Way to Foghorn
Search the scene for the chest. It’s random every playthrough.