This type of question comes up a lot on Blurtit, and the Montgomery Ward UHT J model seems an especially popular make.
The obvious place to start looking or a manual would be with Montgomery Ward themselves, you can reach them on their helpline 877-784-2836.
Their website offers a select number of manuals at wards.com/custserv too.
Aside from Montgomery Ward, there are other sites you can try, either online manual libraries or sewing machine communities. The former includes montgomerywardsmanuals.com, devoted to Wards products.
The online community sites are good places to look for advice, and it they don't have the right manual on hand, a forum user may be able to help you find one.
Homeappliance.manualsonline.com and fixya.com are good for general information, whereas sewusa.com, mastersewusa.com and sewing.patternreview.com offer good support for sewing machine enthusiasts.
For other Blurtit answers to similar questions, check out Where Can I Find A Owner's Manual By Montgomery Wards UHT J-2001? or How Can I Find Sewing Machine Manual For Montgomery Wards Model UHT J 1984? They might be able to give you some extra insight about using similar models.