Mastercraft parts Looking to replace On/Off switch. Saw will not turn off unless power is disconnected?

If you take it to an electrician, the issue may well be the suppressor capacitor, across the switch contact, will be short circuit.
Get it replaced with a suitable Class Y components and it will be working again. OR
thee switch is faulty. Replaceable by a commonly available spare part.
Being 15 years old, there is little hope of a spare parts manual but it is a very basic design and should be easily repaired by a competent engineer.

Contact the manufacturer and ask them to send you an exploded parts diagram and parts list.

Unless you are particularly fortunate you will find the saw is of generic manufacture that has been label engineered without much of a spares service, if any.

You will probably find it quicker and more convenient, perhaps even necessary, to either repair the existing handle or fabricate a new one.

check sears parts on internet

Call Canadian Tire Parts line with the Model etc.
toll-free helpline 1-800-689-9928

Here is a link to the manual
https://www.manualslib.com/manual/1247344/Mastercraft-055-6740-2.html?page=10#manual

Try ereplacementparts.com, or ebay.

I think I may have the same kit (#54-8204-0-).
I called Mastercraft at 1-800-689-9928 and they told me that these were under a 3 year exchange/replacement warranty, and after that we are out of luck (the stores do not stock parts, and unless they have some returned kits around, there may not be parts available).

I asked about the current zip saw (Click this link) and am hoping that parts from that will work. The girl at Mastercraft gave me the number for Powertools plus / JinDing (who make this tool), and I am going to call them and see if I can order the collet that drives the flexible cable (1/4" collet to the small square of the cable).
Their number is 1-877-683-2082.

I am hoping that these are fairly standard, and that the collet will fit.

I went to the Canadian Tire company website and found this number: 1-800-689-9928. I called and it turns out that it is the number for Mastercraft parts, but apparently the table saw (I have one too) is actually made by Porter Cable so don't be shocked when they transfer you to them.

Also, make sure you have the model (or Part) number. It's seven digits (mine is 55-6831-6) but when the roboline asks for it, just put in the first 6.

Hope this helps.

built by canadain tire company their customer service number is 1-866-746-7287 they should be able to get u replacement part and or advise who in ur area can