I have a 1994 model double wide home, and would like to change my 100 amp service to 200 amp service. ( I want to go to electric heat) I have a disconnect at the house after the meter and it say 200amp. Is the wiring from there to my breaker box able to handle 200 amp service, and if not how do I find out? Thanks for any help

2-2/0 for the hots, Neutral could be 1/0, The Breaker Box will also have an Amp Rating on Label. Wiring and Panel will need to be 200 Amp rated.
If you have a 200 amp disconnect, you may have 200 amps to their, and to Panel.
What size wires at the panel?
Why do you think you have 100 amp service?