Hey gamers!!! It’s possible that you’ve come across the MW2 lights through walls glitch, which does exactly what it says it does: it causes the lighting system to become glitchy, which in turn causes lighting effects to be perceived through walls.
The launch of Call of Duty: Modern Warfare 2 was marked by a variety of problems and server troubles, which continue to plague gamers even now, two months after the game’s initial release.

Therefore, if you want to get the game to function properly, you need look into how to repair the glitch that causes lights to shine through walls in MW2.
MW2 Lights Through Walls: How To Fix
There are a few various methods that you may solve the lights through walls bug in MW2, and the severity of these remedies varies.
Because of this, you will want to begin with the simpler fixes first before moving on to the more extensive ones.
We are able to make the assumption that the developers will provide a patch for this issue at some time in the future; but, if you are experiencing it on a regular basis, you will want to take matters into your own hands. See the fixes that are listed below.
Restart Game
The most obvious and straightforward solution is to simply restart your game. This should be sufficient to solve the problem that allows lights to pass through walls as well as many other kinds of bugs.
Restart Mission
In the event that you are experiencing this bug in the single-player campaign, but restarting the mission and then resuming it does not work, you should instead exit the campaign and then restart the mission.
Unfortunately, you will lose progress, but it might be worth it in order to have a game that is functional.
Disable Settings
It is possible that the problem will be resolved completely if you disable the feature known as “on-demand texture streaming” and then restart the game.
There is also the option of restarting the shader cache in your graphics options, followed by restarting the game.
Reinstall

It is possible that the most extreme solution you will need to implement is to uninstall and then reinstall the game; however, you should only attempt this solution if none of the other solutions described above are successful.
You now have a variety of options to choose from in order to get the game back to functioning properly. This concludes our instruction on how to remedy the bug in which lights may be seen through walls in MW2.
Both your time and attention are greatly appreciated. I would appreciate it if you could leave a remark. I am grateful to you.