It might be possible to do so since certain Crypto currencies mining is CPU compatible and smart TVs can install host and run apps.
However the mining capability is not the only criterion that should be taken into account. It is important to look at:
Hardware capacity, known as hashing power.
Hardware cost,
Electricity cost,
Currency price,
Mining processes a massive amount of data every second. TV or similar devices have processors which are not designed to perform such tasks. In most cases, these devices (if they can) will mine at loss.
Reason why no one considers the idea!