The general election has been called for 6th May. It is now too late for a Postal Vote, but:
To Vote by Proxy, please click: http://www.wiltshire.gov.uk/elections-application-to-vote-by-proxy-particular-election.pdf
For an emergency Proxy Vote, click: http://www.wiltshire.gov.uk/late_application_to_vote_by_proxy-5.pdf