On the wiki?
You need to include (once) the shader toolkit script found on this page here
into a script in the script section of your project. Unfortunately there's no addon for a copypaste button for the code block & it's quite large, but there is a .lua file available in the resources table at the bottom which can be opened up in any text editor, which will allow you to do select all & copy.
After you've added that, you can use the various shader functions & shader effects that are currently available to apply various effects to the screen &/or scene objects. See here
The noise function can be found here
Quick note: general screen effects will by default also affect the text & mouse cursors too. If you don't want it to affect them then just create an execute a script in game launch actions containing...
-- this will exclude interfaces, display text & mouse cursors from being affected by the shader.
game.ShaderExclude = eShaderExcludeInterfaces
-- this will exclude display text & mouse cursors from being affected by the shader.
game.ShaderExclude = eShaderExcludeTextsAndCursor
P.P.S: there is a bug in the current build with ShaderExclude. It generates black thumbnails for the save system in which only the cursor can be seen. This has been fixed for the next public build.