Can I piggyback internal lights off each other?

[Gordon1702]

I’m going to be putting my carpet lining in the back of my van now it seems i have plenty time to do it! I’m tempted to buy a couple more of the original lights, and piggy back on to the existing ones, so they work with doors and have the option to turn on and off is this the easiest thing to do?

Thanks

 

[Garny999]

Pictures of existing setup will help. Can you not just link additional lights in series if already wired and working?