SOLVED. YA/Childrens book about a boy whose touch reveals the true forms of members of a secret society [s]

[Ciara]

I read this book in elementary school, sometime around 2012-2014. This is what I remember the basic plot to be:
There's a boy locked in his room because his touch can reveal people's "true form", and he somehow becomes free and ends up in the care of a group who SPOILER..., turn out to be the bad guys. They have something to do with widows, either the group's victims are widows or they recruit widows idk. The boy at some point is at this doctor, who he touches, and the doctor's human form melts away and his form is a large bid thing(?). The boy is being helped by this man who I think was called Mr.Nicely (All the bad guys had names that seemed nice like that) Who ended uo helping him fight the society, My most vivid memory of it is that at the end SPOILER....., the boy is choking the main villan and his true form (this skeleton thing) is coming out, and he says "Not so nice Mr.Nicely" to Mr.Nicely.
For some reason I think it was called something like Birdman, or firebird or something but I could be wrong.

[Becca]

Looks like The Society of Unrelenting Vigilance by Glenn Dakin, first book of the Candle Man series. The baddies who pretend to take care of him are called Dr Saint, Mr Nicely and Clarice.

[Ciara]

THATS IT!! thank you so much omg