I'm switching a 1mA load current that has 24V load voltage. The Control voltage is 5V and is driven from a microcontroller that can also source 24mA. Is it better to use an N Channel MOSFET or a NPN BJT Transistor?
You can use either since your design requirements are easy. But I personally would use an NPN because of the much lower cost and robustness (no gate to zap accidentally).
It does cost an extra resistor for the base but resistors are cheap.