Julia, 17 16 bytes

f(n)=2>rand(1:n)

This is a function that generates a random integer between 1 and n and tests whether it's less than 2. There will be a 1/n chance of this happening, and thus a 1/n chance of returning true.

Saved 1 byte thanks to Thomas Kwa!

Julia, 17 16 15 bytes

n->2>rand(1:n)

This is a function that generates a random integer between 1 and n and tests whether it's less than 2. There will be a 1/n chance of this happening, and thus a 1/n chance of returning true.

Saved 1 byte thanks to Thomas Kwa!

Julia, 17 bytes

f(n)=n==rand(1:n)

This is a function that generates a random integer between 1 and n and tests for equality with n. There will be a 1/n chance of returning true.

Julia, 17 16 bytes

f(n)=2>rand(1:n)

This is a function that generates a random integer between 1 and n and tests whether it's less than 2. There will be a 1/n chance of this happening, and thus a 1/n chance of returning true.

Saved 1 byte thanks to Thomas Kwa!