Other expressions to say "don't get involved with" something or somebody'

I am looking for expressions or idioms to describe a context where you advise someone not to do something (a favor, give help or advice, lend money, etc.) because by doing so he would probably risk getting involved in potential problems that he is not aware of.

Sort of Don't mix with that issue, or you may regret it.

Idiom - If you play with fire, you'll burn your fingers.

Solution 1:

Consider:

• Steer clear of X.
• The risks outweigh the benefits.
• Opening a Pandora's box
• More than you can handle
• That could backfire on you.
• Might bite you in the butt
• Be forewarned.
• Caveat emptor.
• The cure is worse than the disease.
• Sounds good in theory

Solution 2:

Some idioms that may apply depending on context:

"Don't bite off more than you can chew" - by getting involved with whatever or whomever, you may get something more (work, trouble, entanglement) than you are willing to deal with.

"Avoid X like the plague!" - this is an extreme warning as is this...

"Don't touch X with a 10-foot pole!"