When you have your tv on even though you aren't watching anything.
Usually whatever you're wallpaper tv is requires no attention span and has no plot.
wallpaper tv is..
-Tv guide channel
-Any movie you've seen 2 or more times or is more than 7 years old.
-Whatever comes on after something you where actually watching.
-repeates that get shown 900 times a day (friends, madtv, anything on tvland,ect.)

or WW

It's the day in the week, on which you change all your wallpapers.

Stapled, taped or glued beer case packaging on walls to cover up clandestine crime/embarrassing seans, like, but not limited to: bullet holes, blood stains, cum stains and meth-lab remnants.

The pattern of squashed dead mosquitos on your bedroom walls attained through killing them with a folded newspaper on a hot summer night.

The result of a "person with explosive shitsticles comming out of his arse" that continualy smashes his asshole against the wall. This makes a brown masterpiece that some people call the "Dutch Wallpaper"

A psychological warfare tactic of attacking your opponents by creating media or memes made to look like your opponents hold some universally hated or easily defeatable opinion.

When someone is so boring that could easily just melt into the wallpaper.