In general, it's entirely at an employer's discretion as to whether they regard a criminal conviction as relevant when considering an applications for employment. There are a few 'blanket bans' in certain jobs. (e.g. school governors are not allowed any discretion if they receive an application for employment from someone convicted of a sexual offence against a child; they may not employ such a person). However, there are no blanket bans applying to staff in care homes (or in similar environments).
The only duty on the employer is that they must apply 'due diligence' when appointing their staff. (e.g. if they gave a job, caring for elderly people, to someone who'd recently been convicted as a con-man preying on the elderly, they'd risk being sued for negligence if their clients subsequently had money taken from them).
If your conviction for deception relates to, say, providing false information to get a credit card, it's quite likely that (especially in view of the long time which has since elapsed) an employer would regard it as irrelevant when considering your application.
However, if your conviction relates to directly defrauding a vulnerable person, an employer might decide that (irrespective of the time which has elapsed) it indicates that it would be unwise to employ you working with other vulnerable people.
Chris