Is it okay to steal something similar, of what was stolen from you, from the thief? (If you couldn't find the original thing that was stolen from you.) Ex. My neighbor stole my football and denied ever taking it, but my family witnessed him taking it. I never found it again so I couldn't take my football back, but would it be okay if I take one his regular footballs, just like mine but a bit smaller.
Stealing from your thief (aside from recovering your own football) is not a good idea (Islamically, legally, or practically). Theft is a sin---this is uncontested. So the question is essentially whether or not this kind of "revenge theft" is permissible.
This fatwa indicates a lack of consensus on the matter:
Imam Haskafi (Allah have mercy on him) states:
“It will not be permitted for the rightful one to recover his right from other than the actual item that is owed to him. However, Imam Shafi’i has allowed this (to recover one’s right even from other than the actual item that is owed) and his position is more facilitating.”
However, "revenge theft" goes against the spirit of Islam, where forgiveness and charity are central: But if you give [from your right as] charity, then it is better for you, if you only knew. (Qur'an 2:280). Discussing petty theft:
It is best to forgive the person and forget the wrong, for the sake of Allah, seeking its reward with Him.
Qibla.com, sourced from IslamQA.org
Taking back your own football.
If you find your football, it's still legally your football (The thief does not legally own the stolen item..., IslamWeb). Consequently, taking your own property back is not stealing. IslamWeb describes a hadith:
Ahmad and Ibn Majah reported from Samurah that the Prophet (Sallallahu Alaihi wa Sallam) said: “If belongings of someone are stolen or lost and thereafter he finds the same belongings with another person, he (the real owner) is more entitled to take them. In this case, the purchaser will take the price back from the seller."
There might be some exceptions to this in modern law, e.g., a statute of limitations. It also gets a bit messy if the thief goes on to sell the stolen goods: if you take your own property, the buyer might think you stole it from them. There's also complications about not committing a crime (e.g. trespassing) in recovering your property. See Law.SE.
Taking something other than your own football.
If you take something other than your football, then (by definition) you are taking something that is not yours. It's very likely this will be viewed as theft.
Whoever claims something that does not belong to him; he is not one of us, so let him take his place in Hell.
Sunan Ibn Majah 2319 [grade: sahih]
Even if it were Islamically permissible, it's probably still legally theft, which is a crime: Muslims are generally obliged to abide by the laws of the land and the country they live in... (DarulIftaa.com).
Moreover, there's other risks: (a) How does one accurately appraise the value a used football? (b) What if your "revenge theft" results in "revenge revenge theft"?
Stealing is wrong according to Qur'aan and Hadith. The punishment for Stealing is cutting-off the thief's hand.
Taking same thing from the thief is only for body parts. eg: If someone steal your kidney in the name of surgery, then the punishment for this stealing is taking one Kidney from the Thief. cutting his hand is not applicable for body parts. Like that. eye for an eye, tooth for a tooth..
but for a property or money this law wont fit.
I think you can forgive him.