1. Which one is "safer" Incall or Outcall?
2. What is the penalty if you get caught?

The answer to both questions is "it all depends".

1.  LE traps are usually incall.  But your SO could walk in on outcall.  It all depends on your circumstanses.

2.  Penalties?  Arrest, a misdemeanor, maybe jail time, divorce, and the the wrath/scorn of your SO, friends and family.

If these are your concerns, this hobby is not for you.