I also tried wifi in my apartment and it was still very nice ping of around 29.
Maybe your wife has new phone our your kids? If you have wifi router always think about a MAC filter to securely control who has access.
What can also be is that there is an application on your machine which sends lot of data recently outside.
Maybe a trojan or simple things like enabling onedrive, torrent dl or any other app which is synching his state with the net.
Anyhow I connected all my devices via cable, just reliable and less radiation in the room ( this makes people tired).
... the advantages of living in a ..."mayor" area 
(I envy you M8, ... for the "mayor" not the specific ares 
