The note made Audrey cry (Audrey and happynazgul/reddit)

A transgender 15-year-old boy’s incredibly sweet letter to their neighbour has gone viral.

Audrey told PinkNews that she received the message after placing a trans flag on the front of her home in Salt Lake City, Utah.

Audrey chose to show the world that she was not ashamed of her gender identity by flying the pink, blue and white trans flag in her yard.

It was a brave decision, considering that Salt Lake hosts the headquarters of the Mormon Church, which is struggling to accept LGBT+ equality, despite a poll last year showing that young Mormons increasingly approve of same-sex marriage.

And the sight of the flag seemingly affected a local youngster.

The teenager left a letter for Audrey in which they wrote: “Neighbour – Thank you for having a trans flag waving in your yard.

“I am a 15-year-old trans boy living in an unsupportive household, but every time I see your flag, I feel better.”

“I appreciate your existence and pride. THANK YOU,” they added.

“P.S. My handwriting is so bad! I’m sorry!”

Audrey posted a photo of the note on Reddit, saying: “This was left on my doorstep and it brought tears to my eyes. I hear you young man and I hope you keep your chin up!”

Speaking to PinkNews, Audrey said she had “mixed” feelings when she saw the letter.

“I felt crushed that this teenager isn’t getting the support that they deserve, but I also felt truly inspired by them,” said Audrey.

“It must have taken a lot of courage to write the note and drop it off on a stranger’s doorstep.”

She was glad to have brought joy into the teenager’s life, but said it made her “wish more could be done for the author and kids like him.”

“Who knows who is struggling in silence?” Audrey said.

Audrey feels she was lucky that, unlike the youngster, those close to her were accepting of her identity as a trans woman.

“Fortunately for me, my family and friend support system is relatively unchanged compared to before I came out,” she said.

“It breaks my heart to see kids like him have to struggle with an unsupportive family, because having your family on your side makes a world of difference.”

She added: “I genuinely hope that this young man sees the amount of attention and love his letter is receiving.”

Last year, Mormon university professor Ruthie Robertson was fired after refusing to renounce her support for LGBT+ rights.

The adjunct professor at the Mormon Church-affiliated Brigham Young University in Idaho went viral with a pro-LGBT+ Facebook post, upsetting authorities at the institution.

Earlier this month, a lesbian couple attracted praise after they painted their house with rainbow colours to troll allegedly anti-gay neighbours.