The light on my casio g-shock keeps illuminating when I shake it.

It needs professional repair, before the seawater permanently damages the circuitry. Or you just buy a new one.

https://www.google.com/search?q=Gold+Illuminator+A168WG-9W

Support ' Home - CASIO

https://world.casio.com > support

G-SHOCK International Warranty Network. If you have any problems with your G-SHOCK, find out the nearest service center from this list.
‎Manuals · ‎Downloads · ‎About Authenticity Check · ‎FAQs

Parts and Repairs - US - Canada Authorized Service Centers

https://casiosupport.zendesk.com > en-us > articles > 56...
Nov 28, 2022 - East Coast Service Location Casio Factory Service Center (All products) 570 Mt. Pleasant Ave.Dover, NJ 07801

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click here > http://ftp.casio.co.jp/pub/world_manual/wat/en/qw3232.pdf for instructions ........

Try this link: http://world.casio.com/wat/download/en/manual/

If you haven't got instructions on how to do this, you can get
instructions from the Casio web site.

Go to the casio web site "casio.com".

Select "support" and the "manuals",
watches;

Accept terms

Select "watch manual archive"

Read the number of the back of your watch and enter it into the search box

Click on my profile (escapement), then click on Tips and Tricks. There you will find link to all CASIO watch manuals.Rate me, please.

http://world.casio.com/wat/download/en/manual/
?
There are so many aplications use of the manual will be manditory.

Use the four numbers on the back of your watch and you will have a PDF version of your instruction manual.

Hope this tip helps
R/
David
http://antiqueclock.clockstop.com/

I don't think your watch has this sort of option. You can find out yourself by finding CASIO watch manual link in my tips.

Did the same with my DW-003 and thought I'd broken the Illuminator (and the alarm didn't work). Next battery change was via a shop and the illuminator worked again (as did the alarm). This was just a battery cahnge, rather than a repair job - One of those things, I guess

Not a direct solution but you can get the electronic manual for free from http://world.casio.com/wat/download/en/manual/

if you download this manual from casio it may help as the light on the watch can be turned off, although i dont know if thats what happened in your case...if not then you need to see a watch repairer...:)

http://ftp.casio.co.jp/pub/world_manual/wat/en/qw1659.pdf

good luck