adding effect to new item. not weapons or armor

[somebodie]

Ok i've goggled for this, but can only find for adding legendary effects to armor or weapons. I wanted to add an effect to a constructible items. say like sleeping in a bed gives you well rested.

 

how would I add that effect or others to an item I have already added to the game.

 

For example: removing rads from you while you sleep or removing rads overtime.