You Do Need power plug adapter while traveling from Liechtenstein to Tunisia.

Here is Why You Need An Adapter

The outlet and plug type used in Tunisia are C and E and in Liechtenstein are C and J. This is how they look like.

Liechtenstein

In Liechtenstein, outlets of type C and J are in use.

Type C

Type J

Tunisia

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

Type C

Type E