On Sunday, 3 February 2019 08:50:05 UTC, Brian Gaff wrote:

No no fuse just a resistor across the pins to discharge any charge left
when you unplugged it.
It is perfectly possible for a wall-wart containing a mains transformer
to have no fuse but still comply with the relevant safety standards.
For this to be the case the transformer itself must be rated to have
an acceptable temperature rise when its output is shorted.

John