Sewage smell coming threw vents and electrical outlets

[TennerPenner]

In my one bedroom and attached bathroom I have a horrid smell blowing threw the plugs on the walls as well as the vents. I can feel the air pushing threw and the smell is overwhelming. Certain random times the smell gets stronger and then subsides again. I have no idea where to begin with this. What can I do so I can use my bedroom again. Bathroom works well, no issues with the toilet or sink. It is shared wall with my neighbour (I live in a duplex) thought the smell was coming from him until i noticed the vents stank too.

 

[Stuff]

Is it better or worse after you shower/flush? Start in the basement and examine every drain pipe you see. Follow your nose. Could be as simple as the trap for a floor drain has dried out. Could also be a dead rodent in your ducts.

 

[Sponsor]

 

[Reach4]

You might ask the neighbors about what they smell.

How does the wind from the outlets correlated with the outside wind?