If you had the ability to phase or walk through solid objects at will what would you use it for?

If you had the ability to phase or walk through solid objects at will what would you use it for?
If you had the ability to phase or walk through solid objects at will what would you use it for?
Like shadow cat from the xmen franchise. You can phase through solid objects like walls and floors and such.
If you had the ability to phase or walk through solid objects at will what would you use it for?
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