curse_grounding.xml

<statusEffects>
  <statusEffect>
    <name>Curse of Grounding</name>
    <key>curse_grounding</key>
    <type>curse</type>
    <icon>wounds_7</icon>
    <description>
      There is a cursed item in your inventory.
    </description>
    <hasTurns>false</hasTurns>
    <tags>randomItemCurse</tags>
    <modifiers>
      <modifiers>
        <type>CarryWeight</type>
        <amount>-5.0</amount>
      </modifiers>
    </modifiers>
  </statusEffect>
</statusEffects>