v. In the event that following such meeting, the Council decide not to allow and require the match to be played at that ground then the first alternative ground shall be the nearest suitable ground subject to the agreement of the Council.
Taken from http://www.thefa.com/Competitions/FACompetitions/TheFACup/Rules
When smaller clubs were drawn at home to much bigger clubs in the past (up until a decade or so ago), the games were quite frequently switched to the bigger club's ground (e.g. Farnborough Town v Arsenal) citing "safety reasons", which was not entirely accurate. I think the rule was probably brought in to prevent that sort of thing happening.
If it is enforced then the closest free ground would probably be Garforth Town, although alternatives (within about twenty miles) might be:
Selby Town
Harrogate Town (if they lose their replay next week)
Pontefract Collieries
Farsley
Hemsworth Miners Welfare
Guiseley
Askern Villa
Thackley
Osset Albion
Goole
Does any one of those take your fancy?!