A friend's been sick and had not been using his cast iron grill/griddle for approximately 8 years. He decided to give them to me. The grill/griddle was seasoned (with oil) 8 years ago, but the oil on them is now sticky to the touch. If I don't want to get food poisoning, do I need to wash off the old oil with soap? or is it safe to start using the grill/griddle as is? I've attached a picture for reference.  
It won't give you food poisoning, but re-seasoning (rather burning off clean and then immediately re-seasoning) is advisable if sticky (which means, IME, it was oiled and put away 8 years ago, not actually seasoned (heating to polymerize the oil) 8 years ago. The canonical seasoning/re-seasoning cast iron thread here: https://cooking.stackexchange.com/a/647/34242 