If I run arduino projects in my home. Is it risk from home fire ?

My projects plan.

  • 12V wall wart + Arduino or Just MCU with custom PCB + WiFi + temp sensor + rain sensor + relay module + 12v cpu fan + etc...
  • With non-flammable plasticbox contains my project devices.
  • Using fuse for project
  • Avoid direct working with AC or AC devices (AC only at wall wart plug).

If I want to use battery as my power source, Should I avoid using lithium ion battery ?