Is there any way to spawn more lights

Im using the l4d dead before dawn mall for making comics.Inside the mall wasen’t bright so i put in alot of lights.When i was putting half-way.The other light’s gone.Than the new one appear.Is there any way to spawn more lights.

This shouldn’t happen as in singleplayer you can spawn unlimited amounts of everything (Untill your computer crashes of course)

Are you sure you’re not just accidently hitting the key you assigned that turns them on and off?

I can spawn alot of them.But of spawning more and more.Some of the lights isn’t bright anymore and the new one’s become bright.Maybe typing something into the devoluper console.Will fix that.