If you just decorated your place for the holidays and your internet suddenly sucks, you might need to move your router. That's because putting anything in front of your router can cause issues.
So your Christmas tree could be blocking the signal and slowing down your wifi speed. Oh and decorations on the tree like lights and tinsel can make the signal even worse.
What happens is, when the radio waves your router pumps out hit tinsel (or ornaments), they bounce off and scatter, which can slow your WiFi down.
Another pro-tip: Don't plug your Christmas lights into the same outlet as the router. This raises your chances of your connection dropping.
(The Sun)