This function can be used to get or to set the position of an instance along a path. The value is normalised from 0 - 1, so if you set it to, for example, 0.5, the instance will be moved to exactly the middle of the path.
For functions relating to paths, see here.
Real (single precision floating point value)
path_position = random(1);
The above code sets the instance to a random position anywhere on the current path.