A homeowner that is offering their home on contract for deed usually owns the home outright and will sell in this way because they can gain more in interest from the contract than they would if they simply put the money in the bank.
A contact for deed can only be offered on a home when it is completely paid for free and clear. Basically, the seller is acting as the bank and providing the financing directly.
If you can find an investor who has enough cash to purchase a home outright and who is willing to work with you - that might work, but be prepared to pay a higher interest rate, put a substantial amount of money down, and pay a balloon payment at the end of 2 to 5 years.
Also be aware that if something happens and you default, in most cases you only have 30 days vacate the property and you don't get any money back.
Does that make sense?