You Do Need power plug adapter while traveling from Mexico to Western Sahara.

Here is Why You Need An Adapter

The outlet and plug type used in Western Sahara are C and E and in Mexico are A and B. This is how they look like.

Mexico

In Mexico, outlets of type A and B are in use.

Type A

Type B

Western Sahara

In Western Sahara, outlets of type C and E are in use.

Type C

Type E