95 ford escort keeps running when key is turned off???

I bought this 95 ford escort as a easy on gas beater car. When you turn the key off and pull it out of the ignition it keeps running. Sometimes for 2-3 seconds, sometimes as much as 10 seconds. Then it shuts off. It doesn't diesel, It just stays running. Can anyone help with telling me what may be wrong with it???? I think it may be in the wiring.

Ignition switch requires replacement.

By the way, a worn key can cause other issues with the lock cylinder so be sure to keep an unused backup for making new copies.