How does Wayfarer Resonance Tinker work?

[TiwazBlackhand]

I found one thread with no answers, so I'll try a new thread.

Wayfarer Resonance Tinker, LOWorldGuide P.23
Pathfinder Agent feat 4

Lost Omens World Guide wrote:

You can use the unusual resonance of your wayfinder to grant

it additional effects. Choose one cantrip from the arcane,
divine, occult, or primal list. You can activate your wayfinder
to cast that cantrip at will. Additionally, you can Activate your
wayfinder with a [one-action] (envision) activation to transform it into
a nondescript pin or brooch to hide your affiliation with the
Pathfinder Society. This transformation lasts for 1 hour

With regards to the bolded part, do I have to be a spell caster to use this?

Because it reads to me that it's essentially Activate:Cast a Spell, and from looking in the CRB it looks like I need to actually have Cast a Spell from a casting feature to activate an item that way.

If so then I assume my casting stat would be my normal casting stat.

If I can use this ability WITHOUT already being a caster, how do I determine my casting stat for the spell if I pick a combat cantrip?

[Gary Bush]

This functions the same way as a normal Wayfinder, which allows the user to "cast" the Light cantrip. This feats allows a second cantrip of their choice.

There is no requirement to be a spell caster as the item is doing all the work.

[TiwazBlackhand]

Ok, but what if it's a combat cantrip?

If I put Acid Splash in there, and I'm not a spell caster normally, what's my Spell Attack mod?

If I put Electric Arc, what's the Save DC?

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Also, if I'm correct in my initial interpretation, does taking the skill feat Arcane Sense (granting me an innate spell (Detect magic)) then make me enough of a spell caster to trigger items with Activate:Cast a Spell?

[Cordell Kintner]

Gary Bush wrote:

This functions the same way as a normal Wayfinder, which allows the user to "cast" the Light cantrip. This feats allows a second cantrip of their choice.

There is no requirement to be a spell caster as the item is doing all the work.

It's actually not the same. The standard Wayfinder ability is a single action command with the effect: "The wayfinder is targeted by a 1st-level light spell." The feat allows you to Cast the Spell stored in the wayfinder.

The way I read it, you do not need to be proficient in the specific tradition. However, if you aren't proficient you're probably not going to hit with the spell. Think of it as a way to add another cantrip to your daily spell list or repertoire.