You can although the specifics depend a lot on what you're swtiching from. A mechnical engineer, an accountant, a history teacher and a blue-collar worker will need to approach this in very different ways.
I moved from teaching to coding by first working on open source teaching software in my spare time, then using it as part of my teaching work, then getting a junior coding job at a university. I was a better teacher because of the software I was making, and I was a more attractive junior hire due to my domain knowledge.
Code at home --> Use project at old job --> Use domain knowledge plus project to land first coding job --> Coding career :)