Compatibility summary
Your Switzerland plug may fit in Eritrea outlets, as both use at least one common plug type.
Plug comparison
Switzerland plug types: C J
Eritrea plug types: C E L
Both countries share at least one plug type (C J and C E L), so some plugs may work without an adapter. Check your appliance.
Voltage comparison
Switzerland: 230V, 50Hz
Eritrea: 230V, 50Hz
Voltage difference is within a range many devices tolerate; check your appliance label.