The NYT, CNN and WSJ reported Saturday that, recently, federal authorities intercepted a package addressed to the White House with Trump as the target. Two different tests were reportedly done to confirm it was ricin ... a poisonous substance that can be lethal.

The package -- which is said to have arrived in an envelope of some sort -- was reportedly caught early at an off-site mail facility ... some outlets are saying it was sent from a Canadian address. No arrests have been made -- the FBI and the Secret Service are investigating.

This isn't the first time someone has tried sending the natural poison to 1600 Pennsylvania Ave. -- in fact, a Navy vet admitted to doing it in 2018, only that time,  castor beans (from which ricin is derived) were shipped and he ended up getting caught and arrested for it.

Someone also tried sending ricin-laced letters to Barack Obama when he was in office, and got sentenced to 25 years in prison for it back in 2014. Ricin can kill someone by inhaling it, injecting or ingesting it. It was recently made famous and well-known in "Breaking Bad."